The Appendix is intended for use in conjunction with the 2020 Annual Air Quality in Ontario Report. The Appendix briefly describes the provincial Air Quality Health Index (AQHI) network, quality assurance and quality control procedures, and the Ministry of the Environment, Conservation and Parks’ air quality database. It also includes a series of tables displaying station locations and a listing of the summary statistics including means, maximums, percentile values and the number of exceedances of the Ontario Ambient Air Quality Criteria (AAQC) for each pollutant. In addition, trends for select pollutants are displayed for a 10-year period.

Monitoring network operations

Network description

In 2020, the ministry operated 39 ambient air monitoring sites across Ontario as part of the AQHI network. The AQHI network was comprised of 134 continuous monitoring instruments at 39 sites. These instruments have the capability of recording minute data (approximately 70 million data points per year) that are used to scan and validate the continuous hourly data.

Quality assurance and quality control

Day-to-day maintenance and support of the instruments are administered by ministry staff. Instrumentation precision is verified by daily automatic internal zero and span checks. Data analysts and station operators review span control charts to confirm instrument precision using a telemetry system. A quarterly quality assurance and quality control (QA/QC) review is performed on the ambient data set to highlight anomalies and administer corrective action in a timely manner.

The air monitoring station operators routinely inspect and maintain monitoring equipment and stations with mandatory quarterly on-site visits where secondary transfer standards are used to calibrate instrumentation. Station maintenance activities are recorded using FieldWorker Inc. software, an electronic documentation solution; this information is transferred directly to the ministry’s database. The instrumentation used throughout the provincial air monitoring network has been standardized to Thermo Electron Corporation analyzers to streamline parts inventory and leverage common hardware used within each analyzer. The following is a summary of the instrumentation deployed within the network and are all US EPA designated equivalent methods:

  • Nitrogen Oxides – TE42C/I
  • Fine Particulate Matter – SHARP 5030
  • Ozone – TE49C/I
  • Sulphur Dioxide – TE43I
  • Carbon Monoxide – TE48I
  • Total Reduced Sulphur – TE43I/CDN101

The ministry operates a laboratory with gas reference standards that adhere to those of the U.S. National Institute of Standards and Technology (NIST) and the Air Quality Research Division of Environment and Climate Change Canada. The secondary transfer standards used by station operators are referenced and certified to the ministry’s NIST primary standards on a quarterly basis.

The Ontario ambient air quality monitoring network undergoes constant maintenance to ensure a high standard of quality control. Continuous real-time data are consistently reviewed, assessed and validated by ministry staff. Immediate actions are taken to correct any inconsistencies that may affect the validity of the data. These measures ensure ambient air monitoring data are valid, complete, comparable, representative and accurate. As a result, the 2020 ambient air quality monitoring network had 99% valid data from over one million hourly data points.

Data base

The ambient air quality data used in this report are stored in the ministry’s air quality information system (AQUIS) and are made available through the Air Quality Ontario web site, and the Ministry’s Open Data Catalogue. A statistical pattern test is used to identify data anomalies, such as unusual pollutant concentrations. Each pollutant has a predetermined concentration range based on historical data. Values outside this range are flagged for further investigation.

Data are obtained from automated ambient air monitoring instruments that operate continuously to produce an average measurement for every hour for a possible total of 8,760 measurements in a given year. Hourly parameters measured include NO/NO2/NOx, PM2.5, O3, SO2, CO and TRS compounds. An annual mean requires at least 6,570 hourly readings. In addition, each quarter of the year should have 75% valid data for PM2.5, whereas for ozone, only the 2nd and 3rd quarters of the year require 75% valid data based on protocols that are consistent with the Canadian Council of Ministers of the Environment (CCME) and the United States Environmental Protection Agency (U.S. EPA). For VOC samples, half of the method detection limit (MDL) is applied as appropriate to concentrations measured below the detection limit. An annual and/or monthly mean for 24-hour VOC samples require 50% of valid samples.

Network descriptive table

The AQHI network for 2020 is summarized in the 2020 Ontario Continuous Ambient Air Monitoring Network. The table displays the station name, numerical identifier and pollutants measured. The numerical identifier is the station (ID) number, the first digit of which identifies the geographic region in which the station is located. Air monitoring stations within the AQHI network can measure up to six common pollutants (NO2, PM2.5, ozone, SO2, CO and TRS compounds) based on the pollutant(s) of concern for the regional area it represents.

The 2020 Ontario Continuous Ambient Air Monitoring Network also identifies the type of air monitoring site: ambient, roadside, Canadian Ambient Air Quality Standard (CAAQS), and/or National Air Pollution Surveillance (NAPS). Ambient sites represent the general air quality of an area without any direct influence of local industrial sources. Road-side sites are within approximately 100 m of a major roadway with daily traffic volumes greater than 10,000 vehicles per day.

Annual statistics and trends

The annual statistical data and trends for various continuous pollutants and selected volatile organic compounds are presented in the Appendix. The annual averages, maximums and percentiles are displayed in the annual statistics tables. (A percentile is the value equal to or below which a given percentage of the data set falls. For example, if 70% of the data are equal to or below 0.10 ppm, the 70th percentile is 0.10 ppm).

The trends are calculated from monthly means through the Mann-Kendall (M-K) test. The M-K test is a nonparametric statistical approach that can be applied to data without making assumptions on the nature of the data distribution. The M-K test is essentially a test for uniform progression (zero change) in the slope of the linear regression of time-ordered data versus time (Gilbert, 1987). The M-K test is particularly suitable for environmental monitoring data since missing, trace and below detection limit values can be handled. This test can also be used to compare trends at multiple stations. The seasonal Kendall test, also performed in this Report, is a generalization of the M-K test (Gilbert, 1987) for use to determine the true trend when there are seasonal cycles in the data which do not constitute a true long-term trend. The change over time was based on the Sen’s slope, also known as the Thiel-Sen’s estimator of linear trend. The Sen’s slope is closely-related to and applied in conjunction with the M-K Test. Compared to the common least squares regression, the Sen’s slope procedure is a nonparametric method for computing the value of the true slope when there are gross errors or outliers in the data without making assumptions of a normal distribution on the data (Gilbert, 1987).

Other informative tables

Calculated CAAQS metrics for PM2.5, ozone, NO2 and SO2 are presented for 2020 (based on a three-year average, 2018-2020) and over a 10-year period in Canadian Ambient Air Quality Standard Reporting. The air zone management levels associated to each CAAQS reporting pollutant is also provided for reference. The percentage distribution of hourly AQHI readings within the various health risk categories for each of the 39 monitoring sites, and the number of air quality alerts issued in Ontario during 2020 are summarized in AQHI and Air Quality Alert Program Reporting. Traffic volumes and pollutant concentrations over the COVID‑19 pandemic period are presented as well.

2020 air monitoring network

2020 Ontario continuous ambient air monitoring network

ID Station name Station location Year Latitude Longtiude Air intake Type AQHI NO2 PM2.5 O3 SO2 CO TRS
12008 Windsor Downtown 467 University Ave. W. 1969 42°18'58.8" -83°02'37.2" 4 A/RS/C/N Y T T T T T N/A
12016 Windsor West College Ave./South St. 1975 42°17'34.4" -83°04'23.3" 4 A/N Y T T T T N/A T
13001 Chatham 435 Grand Ave. W. 2005 42°24'13.3" -82°12'29.9" 15 A/C/N Y T T T N/A N/A N/A
14111 Sarnia 700 Christina St. N. 2016 42°59'25.0"  -82°23'43.2" 3 A/C/N Y T T T T N/A T
15020 Grand Bend Point Blake Conservation Area 1991 43°19'59.1" -81°44'34.4" 5 A/N Y T T T N/A N/A N/A
15026 London 42 St. Julien St. 2013 42°58'28.1" -81°12'03.1" 5 A/C/N Y T T T N/A N/A N/A
16015 Port Stanley 43665 Dexter Line, Elgin Water T. Plant 2002 42°40'19.5" -81°09'46.4" 5 A/N Y T T T N/A N/A N/A
18007 Tiverton 4th Concession/Bruce Rd. 23 1979 44°18'52.1" -81°32'59.0" 4 A/N Y N/A T T N/A N/A N/A
21005 Brantford 324 Grand River Ave. 2004 43°08'19.0" -80°17'33.5" 5 A/C/N Y T T T N/A N/A N/A
26060 Kitchener West Ave./Homewood Ave.  1990 43°26'37.8" -80°30'13.7" 5 A/C/N Y T T T N/A N/A N/A
27067 St. Catharines Argyle Cres., Pump Stn. 1987 43°09'36.2" -79°14'05.1" 4 A/C/N Y T T T N/A N/A N/A
28028 Guelph Exhibition St./Clark St. W.  2000 43°33'05.8" -80°15'51.0" 4 A/C/N Y T T T N/A N/A N/A
29000 Hamilton Downtown Elgin St./Kelly St.  1987 43°15'28.0" -79°51'42.0" 4 A/RS/C/N Y T T T T T T
29118 Hamilton West Main St. W./Hwy 403 1985 43°15'26.8" -79°54'27.9" 3 A/RS/N Y T T T N/A N/A N/A
29214 Hamilton Mountain 250 Fennell Ave. W. 2019 43°14'28.4" -79°53'21.9" 3 A/C/N Y T T T T N/A N/A
31129 Toronto Downtown 55 John St., Metro Hall 2019 43°38'43.5" -79°23'20.7" 2 A/RS/C/N Y T T T N/A N/A N/A
33003 Toronto East Kennedy Rd./Lawrence Ave. E.  1970 43°44'52.5" -79°16'26.6" 4 A/RS/C/N Y T T T N/A N/A N/A
34021 Toronto North 4905 Dufferin St., ECCC 1988 43°46'53.8" -79°25'03.8" 5 A/RS/C/N Y T T T T T N/A
35125 Toronto West 125 Resources Rd. 2003 43°42'34.0" -79°32'36.6" 8 A/RS/C/N Y T T T T T N/A
44008 Burlington North Shore Blvd. E./Lakeshore Rd.  1979 43°18'54.4" -79°48'09.5" 5 A/C/N Y T T T N/A N/A N/A
44017 Oakville EightLine/Glenashton Dr., Halton Reservoir 2003 43°29'12.9" -79°42'08.2" 12 A/C/N Y T T T N/A N/A N/A
44029 Milton 1120 Main St. E. 2019 43°31'46.7" -79°51'44.8" 4 A/C/N Y T T T T N/A N/A
45027 Oshawa Brittania Ave. W., Ep Taylor Stables 2005 43°57'07.5" -78°54'45.2" 7 A/C/N Y T T T N/A N/A N/A
46090 Brampton 109 Mclaughlin Rd. S. 2000 43°41'55.5" -79°46'51.3" 5 A/C/N Y T T T N/A N/A N/A
46108 Mississauga 3359 Mississauga Rd. N., U of T Campus 2007 43°32'49.1" -79°39'31.3" 5 A/C/N Y T T T N/A N/A N/A
47045 Barrie 83 Perry St. 2001 44°22'56.5" -79°42'08.3" 5 A/C/N Y T T T N/A N/A N/A
48006 Newmarket Eagle St. W./Mccaffrey Rd. 2001 44°02'39.5" -79°28'59.7" 5 A/N Y T T T N/A N/A N/A
49005 Parry Sound 7 Bay St. 2001 45°20'16.3" -80°02'17.4" 5 A/N Y T T T N/A N/A N/A
49010 Dorset 1026 Bellwood Acres Rd. 1981 45°13'27.4" -78°55'58.6" 3 A/N Y N/A T T N/A N/A N/A
51001 Ottawa Downtown Rideau St./Wurtemburg St. 1971 45°26'03.6" -75°40'33.6" 4 A/C/N Y T T T T T N/A
51010 Petawawa Petawawa Research Forest Facility 2007 45°59'48.2" -77°26'28.3" 6 A/N Y N/A T T N/A N/A N/A
52023 Kingston 23 Beechgrove Lane 2014 44°13'11.5" -76°31'16.1" 5 A/C/N Y T T T N/A N/A N/A
54012 Belleville 2 Sidney St., Water Treatment Plant 2002 44°09'01.9" -77°23'43.8" 10 A/N Y T T T N/A N/A N/A
56051 Cornwall Bedford St./3rd St. W. 1970 45°01'04.7" -74°44'06.8" 4 A/N Y T T T N/A N/A N/A
59006 Peterborough 10 Hospital Dr. 1998 44°18'06.9" -78°20'46.4" 10 A/C/N Y T T T N/A N/A N/A
63203 Thunder Bay 421 James St. S.  2004 48°22'45.8" -89°17'24.6" 15 A/RS/C/N Y T T T N/A N/A N/A
71078 Sault Ste. Marie Sault College 2004 46°31'59.5" -84°18'35.7" 8 A/C/N Y T T T T N/A T
75010 North Bay Chippewa St. W., Dept. National Defence 1979 46°19'23.5" -79°26'57.4" 4 A/RS/N Y T T T N/A N/A N/A
77233 Sudbury 155 Elm St. 2013 46°29'31.0" -81°00'11.2" 3 A/C/N Y T T T T N/A N/A
Total               39 36 39 39 11 5 4

Notes:

ID
station identfication number
Year
year station began monitoring
Air intake
height of air intake above ground (m)
Type
type of monitoring site
A
ambient
RS
road-side
C
Canadian Ambient Air Quality Standard (CAAQS)
N
National Air Pollution Surveillance (NAPS)
AQHI
Air Quality Health Index
T
telemetry
NO2
nitrogen dioxide
PM2.5
fine particulate matter
O3
ground-level ozone
SO2
sulphur dioxide
CO
carbon monoxide
TRS
total reduced sulphur
Y
yes

2020 annual statistics

2020 nitric oxide (NO) annual statistics

Unit: parts per billion (ppb)

ID City Location Valid h 10% 30% 50% 70% 90% 99% Mean Max 1h Max 24h
12008 Windsor Downtown 467 University Ave. W. 8701 0.0 0.3 0.6 1.2 3.5 19.0 1.70 179.7 34.1
12016 Windsor West College Ave./South St. 8633 0.1 0.2 0.5 1.0 3.3 23.2 1.70 117.3 28.2
13001 Chatham 435 Grand Ave. W. 8742 0.3 0.5 0.7 1.2 3.2 14.0 1.51 38.1 12.3
14111 Sarnia 700 Christina St. N. 8698 0.4 0.6 0.9 1.5 3.1 10.1 1.58 64.8 9.3
15020 Grand Bend Point Blake Conservation Area 8707 0.2 0.3 0.3 0.4 0.7 2.1 0.42 14.6 1.9
15026 London 42 St. Julien St. 8720 0.0 0.1 0.3 0.5 1.2 8.4 0.68 72.2 9.3
16015 Port Stanley 43665 Dexter Line, Elgin Water T. Plt 8694 0.0 0.0 0.1 0.2 0.8 2.1 0.27 8.2 1.7
21005 Brantford 324 Grand River Ave. 8684 0.1 0.2 0.3 0.5 1.4 9.4 0.78 61.4 10.1
26060 Kitchener West Ave./Homewood Ave. 8655 0.0 0.1 0.2 0.4 1.4 8.5 0.66 55.9 6.9
27067 St. Catharines Argyle Cres., Pump Stn. 8729 0.1 0.3 0.5 0.7 1.4 11.1 0.91 59.6 11.4
28028 Guelph Exhibition St./Clark St. W. 8719 0.0 0.1 0.2 0.4 1.2 11.2 0.75 77.5 16.9
29000 Hamilton Downtown Elgin St./Kelly St. 8759 0.2 0.6 1.0 2.0 6.8 30.0 2.89 127.2 40.6
29118 Hamilton West Main St. W./Hwy 403 8674 0.0 0.3 0.9 2.2 7.4 38.6 3.15 133.6 37.7
29214 Hamilton Mountain 250 Fennell Ave. W. 8721 0.2 0.3 0.5 0.9 3.0 14.1 1.35 51.4 10.2
31129 Toronto Downtown 55 John St. 8628 1.0 1.7 2.8 5.0 11.8 35.5 5.18 113.6 23.0
33003 Toronto East Kennedy Rd./Lawrence Ave. E. 8713 0.0 0.2 0.7 1.7 4.8 28.8 2.31 187.2 46.3
34021 Toronto North 4905 Dufferin St., ECCC 8688 0.1 0.4 0.7 1.4 3.9 28.0 2.12 138.4 28.2
35125 Toronto West 125 Resources Rd. 8681 0.1 0.6 1.9 4.4 12.7 49.2 5.15 139.3 40.1
44008 Burlington North Shore Blvd. E./Lakeshore Rd. 8771 0.2 0.7 1.1 1.9 4.6 21.9 2.26 94.7 18.2
44017 Oakville EightLine/Glenashton Dr., Halton Res. 8743 0.1 0.4 0.5 0.8 2.4 15.6 1.25 58.7 14.8
44029 Milton 1120 Main St. E. 8541 0.3 0.4 0.7 1.3 4.7 42.9 2.68 141.0 40.4
45027 Oshawa Brittania Ave. W., EP Taylor Stables 8508 0.0 0.2 0.3 0.6 1.6 10.9 0.85 94.6 7.1
46090 Brampton 109 McLaughlin Rd. S. 8719 0.0 0.0 0.2 0.4 2.4 25.5 1.35 89.4 29.6
46108 Mississauga 3359 Mississauga Rd. N., U of T Campus 8719 0.0 0.2 0.4 0.6 2.6 22.3 1.42 124.8 34.6
47045 Barrie 83 Perry St. 8714 0.1 0.2 0.4 0.8 2.2 20.3 1.36 106.3 14.7
48006 Newmarket Eagle St. W./McCaffrey Rd. 8724 0.0 0.1 0.2 0.4 1.3 13.3 0.77 51.5 9.7
49005 Parry Sound 7 Bay St. 8710 0.0 0.1 0.2 0.3 0.7 5.7 0.44 42.2 6.0
51001 Ottawa Downtown Rideau St./Wurtemburg St. 8770 0.3 0.5 0.7 1.1 2.4 13.7 1.41 80.5 26.1
52023 Kingston 23 Beechgrove Lane 8715 0.2 0.3 0.4 0.6 1.3 4.5 0.66 40.9 6.1
54012 Belleville 2 Sidney St., Water Treatment Plant 8744 0.3 0.3 0.4 0.7 2.5 17.5 1.38 84.0 42.6
56051 Cornwall Bedford St./3rd St. W. 8718 0.1 0.2 0.3 0.5 1.6 23.4 1.22 119.4 30.0
59006 Peterborough 10 Hospital Dr. 8362 0.0 0.1 0.3 0.6 2.0 12.7 0.98 118.8 16.0
63203 Thunder Bay 421 James St. S. 8759 0.5 0.7 1.1 2.1 8.8 32.0 3.39 156.5 24.9
71078 Sault Ste. Marie Sault College 8497 0.1 0.6 1.0 1.4 3.1 12.7 1.58 58.0 8.4
75010 North Bay Chippewa St. W., Dept. National Defence 8766 0.3 0.5 0.6 1.0 2.3 15.4 1.38 78.9 13.6
77233 Sudbury 155 Elm St. 8699 0.4 0.6 1.0 1.6 4.4 27.9 2.38 100.9 25.4

2020 nitrogen dioxide (NO2) annual statistics

Unit: parts per billion (ppb)
NO2 1h AAQC: 200 ppb
NO2 24h AAQC: 100 ppb

ID City Location Valid h 10% 30% 50% 70% 90% 99% Mean Max 1h Max 24h Number of times above 1h criteria Number of times above 24h criteria
12008 Windsor Downtown 467 University Ave. W. 8701 3.3 5.1 7.1 10.2 17.3 31.0 8.99 45.8 24.2 0 0
12016 Windsor West College Ave./South St. 8633 2.6 4.2 6.2 9.4 16.5 29.7 8.14 44.7 23.5 0 0
13001 Chatham 435 Grand Ave. W. 8742 1.9 2.9 4.0 5.8 9.4 18.7 5.05 31.0 16.0 0 0
14111 Sarnia 700 Christina St. N. 8698 0.8 2.1 4.0 7.0 13.9 25.6 5.89 38.5 21.8 0 0
15020 Grand Bend Point Blake Conservation Area 8707 0.4 1.0 1.7 2.8 4.7 9.9 2.28 28.9 9.1 0 0
15026 London 42 St. Julien St. 8720 1.2 2.4 3.6 5.2 8.6 18.3 4.50 38.6 18.9 0 0
16015 Port Stanley 43665 Dexter Line, Elgin Water T. Plt 8694 1.0 1.6 2.2 3.0 4.7 9.6 2.63 18.2 7.8 0 0
21005 Brantford 324 Grand River Ave. 8684 1.5 2.4 3.2 4.5 8.4 18.3 4.30 36.5 19.8 0 0
26060 Kitchener West Ave./Homewood Ave. 8655 1.3 2.3 3.6 5.4 9.7 22.6 4.87 39.2 23.2 0 0
27067 St. Catharines Argyle Cres., Pump Stn. 8729 2.0 2.9 4.0 5.7 10.1 24.0 5.33 37.9 18.5 0 0
28028 Guelph Exhibition St./Clark St. W. 8719 1.3 2.3 3.5 5.5 10.0 22.8 4.88 38.4 25.0 0 0
29000 Hamilton Downtown Elgin St./Kelly St. 8759 3.1 5.0 7.6 11.6 20.2 33.4 9.87 46.7 35.5 0 0
29118 Hamilton West Main St. W./Hwy 403 8674 2.9 4.9 7.3 11.3 19.3 31.9 9.45 45.7 31.3 0 0
29214 Hamilton Mountain 250 Fennell Ave. W. 8721 1.7 2.9 4.6 7.9 15.6 30.0 6.91 47.5 23.2 0 0
31129 Toronto Downtown 55 John St. 8628 4.7 7.5 10.5 14.5 22.2 39.1 12.34 58.8 38.0 0 0
33003 Toronto East Kennedy Rd./Lawrence Ave. E. 8713 2.2 4.0 6.1 9.5 17.8 36.2 8.41 63.9 32.2 0 0
34021 Toronto North 4905 Dufferin St., ECCC 8688 2.6 4.4 6.7 10.1 18.7 34.4 8.89 54.7 31.6 0 0
35125 Toronto West 125 Resources Rd. 8681 3.4 6.6 9.8 14.6 24.1 40.6 12.10 51.6 34.8 0 0
44008 Burlington North Shore Blvd. E./Lakeshore Rd. 8771 2.5 4.3 6.4 9.3 16.3 31.5 8.21 46.0 25.2 0 0
44017 Oakville EightLine/Glenashton Dr., Halton Res. 8743 2.0 3.2 4.8 7.3 14.1 30.3 6.76 45.5 27.8 0 0
44029 Milton 1120 Main St. E. 8541 2.1 3.5 5.2 8.1 16.6 33.2 7.57 47.1 26.8 0 0
45027 Oshawa Brittania Ave. W., EP Taylor Stables 8508 0.9 1.6 2.5 4.1 7.7 15.7 3.61 29.5 15.8 0 0
46090 Brampton 109 McLaughlin Rd. S. 8719 1.3 2.5 4.1 7.1 16.0 36.2 6.75 51.0 35.8 0 0
46108 Mississauga 3359 Mississauga Rd. N., U of T Campus 8719 1.9 3.2 4.8 7.5 13.6 27.8 6.67 43.1 26.1 0 0
47045 Barrie 83 Perry St. 8714 1.5 2.4 3.6 6.0 12.0 29.4 5.58 47.1 24.8 0 0
48006 Newmarket Eagle St. W./McCaffrey Rd. 8724 0.8 1.6 2.6 4.6 10.0 28.0 4.49 42.3 23.5 0 0
49005 Parry Sound 7 Bay St. 8710 0.5 1.0 1.5 2.4 5.0 15.1 2.39 36.7 12.6 0 0
51001 Ottawa Downtown Rideau St./Wurtemburg St. 8770 1.4 2.5 3.8 6.5 13.1 29.2 5.92 49.6 26.8 0 0
52023 Kingston 23 Beechgrove Lane 8715 1.0 1.6 2.3 3.4 7.1 20.2 3.45 41.3 14.9 0 0
54012 Belleville 2 Sidney St., Water Treatment Plant 8744 0.9 1.4 2.2 3.6 7.6 20.5 3.53 36.4 17.3 0 0
56051 Cornwall Bedford St./3rd St. W. 8718 1.1 1.7 2.7 4.4 9.9 29.6 4.59 51.9 26.6 0 0
59006 Peterborough 10 Hospital Dr. 8362 0.8 1.5 2.5 4.2 9.0 24.5 4.05 49.2 25.3 0 0
63203 Thunder Bay 421 James St. S. 8759 1.2 2.3 3.9 6.6 14.0 32.8 6.11 55.3 26.7 0 0
71078 Sault Ste. Marie Sault College 8497 1.0 1.6 2.5 3.8 7.8 17.7 3.67 36.9 15.1 0 0
75010 North Bay Chippewa St. W., Dept. National Defence 8766 0.9 1.5 2.4 4.1 9.2 29.4 4.26 44.9 24.0 0 0
77233 Sudbury 155 Elm St. 8699 1.5 2.5 3.7 6.1 14.0 37.8 6.28 55.8 25.9 0 0

2020 nitrogen oxides (NOx) annual statistics

Unit: parts per billion (ppb)

ID City Location Valid h 10% 30% 50% 70% 90% 99% Mean Max 1h Max 24h
12008 Windsor Downtown 467 University Ave. W. 8701 3.7 5.7 8.0 11.5 20.0 47.9 10.7 212.3 54.7
12016 Windsor West College Ave./South St. 8633 2.9 4.8 7.0 10.6 19.2 48.3 9.9 154.0 51.7
13001 Chatham 435 Grand Ave. W. 8742 2.4 3.5 5.0 7.3 12.1 28.8 6.6 60.6 21.8
14111 Sarnia 700 Christina St. N. 8698 1.5 3.0 5.1 8.6 16.9 31.5 7.5 91.6 26.1
15020 Grand Bend Point Blake Conservation Area 8707 0.6 1.3 2.1 3.2 5.4 11.6 2.7 37.7 10.1
15026 London 42 St. Julien St. 8720 1.5 2.6 4.0 5.7 9.7 24.4 5.2 105.5 28.2
16015 Port Stanley 43665 Dexter Line, Elgin Water T. Plt 8694 1.1 1.7 2.3 3.3 5.4 10.9 2.9 23.9 8.9
21005 Brantford 324 Grand River Ave. 8684 1.8 2.7 3.6 5.1 9.9 24.8 5.1 92.4 29.9
26060 Kitchener West Ave./Homewood Ave. 8655 1.5 2.6 3.9 6.0 10.9 29.5 5.5 84.9 28.4
27067 St. Catharines Argyle Cres., Pump Stn. 8729 2.4 3.3 4.5 6.3 11.4 32.2 6.2 90.4 28.4
28028 Guelph Exhibition St./Clark St. W. 8719 1.5 2.5 3.8 5.9 11.0 33.1 5.6 97.0 34.0
29000 Hamilton Downtown Elgin St./Kelly St. 8759 3.7 5.8 8.7 14.0 26.1 58.7 12.8 161.1 64.8
29118 Hamilton West Main St. W./Hwy 403 8674 3.1 5.4 8.7 14.1 25.9 64.7 12.6 159.8 59.6
29214 Hamilton Mountain 250 Fennell Ave. W. 8721 2.1 3.4 5.2 9.0 18.2 41.5 8.3 85.7 32.5
31129 Toronto Downtown 55 John St. 8628 6.2 9.8 13.6 19.6 32.8 70.3 17.5 157.7 60.1
33003 Toronto East Kennedy Rd./Lawrence Ave. E. 8713 2.4 4.7 7.2 11.2 21.4 59.1 10.7 251.1 78.5
34021 Toronto North 4905 Dufferin St., ECCC 8688 3.1 5.2 7.8 11.4 22.0 57.3 11.0 162.7 55.9
35125 Toronto West 125 Resources Rd. 8681 3.8 8.1 12.4 18.9 35.5 83.0 17.2 173.1 73.4
44008 Burlington North Shore Blvd. E./Lakeshore Rd. 8771 3.1 5.1 7.7 11.2 20.5 50.4 10.5 126.3 41.7
44017 Oakville EightLine/Glenashton Dr., Halton Res. 8743 2.4 3.7 5.4 8.2 16.2 42.9 8.0 88.5 41.0
44029 Milton 1120 Main St. E. 8541 2.6 4.2 6.2 9.6 21.2 70.5 10.3 183.6 61.4
45027 Oshawa Brittania Ave. W., EP Taylor Stables 8508 1.1 2.0 3.0 4.7 9.2 22.4 4.5 109.6 20.8
46090 Brampton 109 McLaughlin Rd. S. 8719 1.4 2.6 4.4 7.8 18 59.5 8.09 134.2 65.3
46108 Mississauga 3359 Mississauga Rd. N., U of T Campus 8719 2.1 3.6 5.2 8.1 16 46.4 8.02 145.0 54.5
47045 Barrie 83 Perry St. 8714 1.8 2.9 4.2 6.7 14 46.5 6.94 139.3 35.3
48006 Newmarket Eagle St. W./McCaffrey Rd. 8724 0.9 1.8 2.9 5 11 39.5 5.22 78.1 33.1
49005 Parry Sound 7 Bay St. 8710 0.6 1.1 1.7 2.7 5.9 18.7 2.82 66.4 18.6
51001 Ottawa Downtown Rideau St./Wurtemburg St. 8770 1.9 3.1 4.7 7.7 15 41.0 7.33 128.7 47.0
52023 Kingston 23 Beechgrove Lane 8715 1.3 1.9 2.7 4 8.2 24.1 4.12 73.0 19.8
54012 Belleville 2 Sidney St., Water Treatment Plant 8744 1.2 1.9 2.8 4.5 10 37.0 4.91 106.0 56.5
56051 Cornwall Bedford St./3rd St. W. 8718 1.3 2 3.1 5.1 12 48.4 5.81 171.3 55.1
59006 Peterborough 10 Hospital Dr. 8362 0.9 1.8 2.9 4.9 11 35.0 5.02 167.9 41.2
63203 Thunder Bay 421 James St. S. 8759 1.9 3.3 5.3 9.2 23 56.8 9.51 211.8 48.4
71078 Sault Ste. Marie Sault College 8497 1.6 2.4 3.5 5.4 11 28.6 5.24 90.3 19.4
75010 North Bay Chippewa St. W., Dept. National Defence 8766 1.3 2.1 3.2 5.3 12 41.2 5.63 120.9 37.6
77233 Sudbury 155 Elm St. 8699 2.1 3.3 4.8 7.8 18 62.4 8.66 156.7 50.7

2020 fine particulate matter (PM2.5) annual statistics

Unit: micrograms per cubic metre (μg/m3)
PM2.5 24h AAQC: 27 μg/m3
PM2.5 Annual AAQC: 8.8 μg/m3

ID City Location Valid h 10% 30% 50% 70% 90% 99% Mean Max 1h Max 24h Number of times above 24h AAQC Number of times above 1 year AAQC
12008 Windsor Downtown 467 University Ave. W. 8722 2 4 6 8 13 23 7.1 42 29 1 0
12016 Windsor West College Ave./South St. 8375 2 5 8 11 16 27 8.8 68 32 3 0
13001 Chatham 435 Grand Ave. W. 8699 2 3 5 8 13 25 6.7 39 22 0 0
14111 Sarnia 700 Christina St. N. 8757 2 3 6 9 15 26 7.1 74 23 0 0
15020 Grand Bend Point Blake Conservation Area 8619 2 2 4 6 10 17 4.8 24 15 0 0
15026 London 42 St. Julien St. 8693 2 4 5 8 13 22 6.5 49 28 1 0
16015 Port Stanley 43665 Dexter Line, Elgin Water T. Plt 8586 2 3 5 8 13 24 6.5 49 22 0 0
18007 Tiverton 4th Concession/Bruce Rd. 23 8442 2 2 4 6 10 17 4.8 30 16 0 0
21005 Brantford 324 Grand River Ave. 8690 2 4 6 8 13 23 6.7 50 26 0 0
26060 Kitchener West Ave./Homewood Ave. 8753 2 3 5 8 13 24 6.6 44 29 1 0
27067 St. Catharines Argyle Cres., Pump Stn. 8685 2 4 5 8 12 22 6.3 44 22 0 0
28028 Guelph Exhibition St./Clark St. W. 8702 1 3 5 9 15 27 6.9 56 31 2 0
29000 Hamilton Downtown Elgin St./Kelly St. 8748 2 4 7 10 16 29 8.1 51 33 1 0
29118 Hamilton West Main St. W./Hwy 403 8626 2 4 7 9 15 28 7.8 50 31 1 0
29214 Hamilton Mountain 250 Fennell Ave. W. 8743 2 4 6 9 14 25 7.1 47 26 0 0
31129 Toronto Downtown 55 John St. 8627 3 5 6 9 14 27 7.6 47 29 2 0
33003 Toronto East Kennedy Rd./Lawrence Ave. E. 8721 1 3 5 8 14 26 6.7 51 27 0 0
34021 Toronto North 4905 Dufferin St., ECCC 8689 1 3 5 8 13 26 6.4 52 27 1 0
35125 Toronto West 125 Resources Rd. 8675 2 4 6 8 13 24 6.9 53 28 1 0
44008 Burlington North Shore Blvd. E./Lakeshore Rd. 8762 2 3 5 8 13 23 6.4 46 25 0 0
44017 Oakville EightLine/Glenashton Dr., Halton Res. 8672 2 4 5 7 12 23 6.3 47 25 0 0
44029 Milton 1120 Main St. E. 8504 2 4 6 8 14 27 7.1 48 32 1 0
45027 Oshawa Brittania Ave. W., EP Taylor Stables 8700 2 4 5 7 12 22 6.2 43 21 0 0
46090 Brampton 109 McLaughlin Rd. S. 8749 2 4 5 8 13 25 6.7 65 25 0 0
46108 Mississauga 3359 Mississauga Rd. N., U of T Campus 8748 1 3 5 8 14 25 6.6 44 29 1 0
47045 Barrie 83 Perry St. 8363 2 3 5 8 14 27 6.8 45 29 1 0
48006 Newmarket Eagle St. W./McCaffrey Rd. 8747 2 3 5 7 12 22 5.9 47 26 0 0
49005 Parry Sound 7 Bay St. 8673 1 2 3 6 10 19 4.4 29 18 0 0
49010 Dorset 1026 Bellwood Acres Rd. 8622 1 2 3 5 9 17 4.5 39 16 0 0
51001 Ottawa Downtown Rideau St./Wurtemburg St. 8726 2 3 5 7 12 24 6.0 41 27 1 0
51010 Petawawa Petawawa Research Forest Facility 8556 1 2 3 5 8 13 4.2 22 12 0 0
52023 Kingston 23 Beechgrove Lane 8587 2 3 4 7 11 21 5.6 32 17 0 0
54012 Belleville 2 Sidney St., Water Treatment Plant 8578 2 3 5 8 13 23 6.3 34 22 0 0
56051 Cornwall Bedford St./3rd St. W. 8731 2 4 5 7 11 22 6.0 42 24 0 0
59006 Peterborough 10 Hospital Dr. 8386 1 2 4 7 13 23 5.6 48 19 0 0
63203 Thunder Bay 421 James St. S. 8697 2 3 4 6 10 20 5.5 48 15 0 0
71078 Sault Ste. Marie Sault College 8749 2 2 3 5 9 16 4.5 43 17 0 0
75010 North Bay Chippewa St. W., Dept. National Defence 8744 1 2 4 5 9 17 4.6 34 18 0 0
77233 Sudbury 155 Elm St. 8730 2 3 4 6 10 20 5.1 41 20 0 0

Notes

  • Measurements taken by SHARP 5030.
  • The PM2.5 AAQC values, based on the 24-hour PM2.5 Canadian Ambient Air Quality Standard (CAAQS), are used "as is" for comparison to an average concentration in a year.

2020 ground-level ozone (O3) annual statistics

Unit: parts per billion (ppb)
O3 1h AAQC: 80 ppb

ID City Location Valid h 10% 30% 50% 70% 90% 99% Mean Max 1h Max 24h Number of times above 1h criterion
12008 Windsor Downtown 467 University Ave. W. 8705 12 21 27 32 43 64 27.3 81 53 1
12016 Windsor West College Ave./South St. 8644 11 20 26 31 41 61 26.0 83 49 2
13001 Chatham 435 Grand Ave. W. 8744 15 23 28 34 43 61 29.1 77 56 0
14111 Sarnia 700 Christina St. N. 8719 13 21 26 32 39 62 26.7 82 49 1
15020 Grand Bend Point Blake Conservation Area 8709 17 25 31 36 43 65 30.9 93 55 12
15026 London 42 St. Julien St. 8648 11 22 28 34 42 60 27.7 77 50 0
16015 Port Stanley 43665 Dexter Line, Elgin Water T. Plt 8669 17 25 31 36 44 61 30.9 76 53 0
18007 Tiverton 4th Concession/Bruce Rd. 23 8510 18 26 31 35 41 58 30.5 75 52 0
21005 Brantford 324 Grand River Ave. 8716 12 22 28 34 43 60 28.0 74 49 0
26060 Kitchener West Ave./Homewood Ave. 8697 14 22 28 33 40 57 27.7 74 46 0
27067 St. Catharines Argyle Cres., Pump Stn. 8730 15 25 30 36 45 60 30.2 75 54 0
28028 Guelph Exhibition St./Clark St. W. 8711 13 22 27 32 41 59 27.0 70 49 0
29000 Hamilton Downtown Elgin St./Kelly St. 8752 11 20 26 32 41 58 26.3 77 52 0
29118 Hamilton West Main St. W./Hwy 403 8689 8 19 26 31 41 58 25.2 76 50 0
29214 Hamilton Mountain 250 Fennell Ave. W. 8742 14 23 29 35 44 61 29.3 79 53 0
31129 Toronto Downtown 55 John St. 8632 10 18 24 29 38 57 24.2 76 48 0
33003 Toronto East Kennedy Rd./Lawrence Ave. E. 8717 11 20 26 32 40 59 26.1 77 51 0
34021 Toronto North 4905 Dufferin St., ECCC 8704 9 19 26 32 41 62 26.0 95 52 9
35125 Toronto West 125 Resources Rd. 8663 6 16 23 30 39 58 23.4 81 47 1
44008 Burlington North Shore Blvd. E./Lakeshore Rd. 8757 12 22 28 34 43 63 28.3 86 51 2
44017 Oakville EightLine/Glenashton Dr., Halton Res. 8739 13 22 28 33 41 60 28.0 81 51 1
44029 Milton 1120 Main St. E. 8514 9 21 27 33 42 61 26.8 77 49 0
45027 Oshawa Brittania Ave. W., EP Taylor Stables 8754 9 20 27 33 40 62 26.4 88 47 4
46090 Brampton 109 McLaughlin Rd. S. 8692 12 22 29 35 43 62 28.4 83 53 3
46108 Mississauga 3359 Mississauga Rd. N., U of T Campus 8720 8 20 26 32 40 57 25.6 80 47 0
47045 Barrie 83 Perry St. 8750 10 20 26 32 39 55 25.9 70 48 0
48006 Newmarket Eagle St. W./McCaffrey Rd. 8722 14 23 29 34 41 60 28.5 87 54 3
49005 Parry Sound 7 Bay St. 8717 16 25 30 36 43 57 29.9 73 50 0
49010 Dorset 1026 Bellwood Acres Rd. 8694 10 21 28 34 42 53 27.1 66 43 0
51001 Ottawa Downtown Rideau St./Wurtemburg St. 8770 10 19 26 31 39 53 25.2 64 51 0
51010 Petawawa Petawawa Research Forest Facility 8776 11 21 28 34 41 51 26.9 63 45 0
52023 Kingston 23 Beechgrove Lane 8715 17 25 30 35 43 58 30.1 72 53 0
54012 Belleville 2 Sidney St., Water Treatment Plant 8744 15 24 30 35 43 61 29.7 81 53 1
56051 Cornwall Bedford St./3rd St. W. 8718 12 21 27 32 40 51 26.4 62 48 0
59006 Peterborough 10 Hospital Dr. 8351 14 22 28 33 40 54 27.6 87 49 2
63203 Thunder Bay 421 James St. S. 8756 8 18 24 29 36 44 22.9 56 44 0
71078 Sault Ste. Marie Sault College 8756 14 23 29 34 40 57 28.2 77 58 0
75010 North Bay Chippewa St. W., Dept. National Defence 8764 10 21 27 32 40 52 26.2 74 49 0
77233 Sudbury 155 Elm St. 8698 10 19 25 31 38 51 24.8 62 53 0

2020 sulphur dioxide (SO2) annual statistics

Unit: parts per billion (ppb)
SO2 10 min AAQC: 67 ppb
SO2 1h AAQC: 40 ppb
SO2 1y AAQC: 4 ppb

ID City Location Valid h 10% 30% 50% 70% 90% 99% Mean Max 10 min Max 1h Max 24h Number of times above 10 min criteria Number of times above 1h criteria Number of times above annual criteria
12008 Windsor Downtown 467 University Ave. W. 8707 0.0 0.0 0.1 0.2 0.8 4.3 0.32 29.1 19.6 2.3 0 0 0
12016 Windsor West College Ave./South St. 8397 0.1 0.2 0.3 0.7 1.7 7.5 0.81 46.2 32.2 8.2 0 0 0
14111 Sarnia 700 Christina St. N. 8718 0.0 0.1 0.2 0.5 3.5 37.6 1.97 93.2 84.4 44.8 98 74 0
29000 Hamilton Downtown Elgin St./Kelly St. 8737 0.0 0.2 0.5 1.2 11.8 41.9 3.65 144.5 89.7 30.8 107 109 0
29214 Hamilton Mountain 250 Fennell Ave. W. 8734 0.0 0.0 0.2 0.8 8.2 28.7 2.45 107.0 84.6 24.3 14 20 0
34021 Toronto North 4905 Dufferin St., ECCC 8694 0.0 0.0 0.0 0.1 0.4 1.8 0.15 10.3 7.9 1.5 0 0 0
35125 Toronto West 125 Resources Rd. 8569 0.0 0.0 0.1 0.2 0.4 1.8 0.19 13.8 10.0 1.6 0 0 0
44029 Milton 1120 Main St. E. 4367 0.3 0.4 0.5 0.6 1.3 3.4 INS 10.6 7.2 2.0 0 0 0
51001 Ottawa Downtown Rideau St./Wurtemburg St. 8769 0.0 0.0 0.1 0.1 0.3 0.8 0.12 5.1 4.0 0.8 0 0 0
71078 Sault Ste. Marie Sault College 8755 0.2 0.3 0.3 0.4 0.7 8.0 0.63 48.2 29.8 5.3 0 0 0
77233 Sudbury 155 Elm St. 8129 0.1 0.2 0.3 0.4 1.7 12.0 0.90 122.9 60.0 8.7 15 3 0

2020 carbon monoxide (CO) annual statistics

Unit: parts per million (ppm)
CO 1h AAQC: 30 ppm
CO 8h AAQC: 13 ppm

ID City Location Valid h 10% 30% 50% 70% 90% 99% Mean Max 1h Max 8h Number of times above 1h criteria Number of times above 8h criteria
12008 Windsor Downtown 467 University Ave. W. 8423 0.14 0.17 0.19 0.22 0.28 0.50 0.21 1.23 0.69 0 0
29000 Hamilton Downtown Elgin St./Kelly St. 8761 0.14 0.16 0.19 0.23 0.34 0.58 0.22 1.22 0.69 0 0
34021 Toronto North 4905 Dufferin St., ECCC 8618 0.14 0.16 0.18 0.21 0.27 0.44 0.19 1.00 0.84 0 0
35125 Toronto West 125 Resources Rd. 8504 0.15 0.18 0.20 0.23 0.31 0.54 0.22 1.55 1.15 0 0
51001 Ottawa Downtown Rideau St./Wurtemburg St. 8691 0.12 0.15 0.17 0.20 0.26 0.47 0.18 0.86 0.65 0 0

2020 total reduced sulphur (TRS) compounds annual statistics

Unit: parts per billion (ppb)

ID City Location Valid h 10% 30% 50% 70% 90% 99% Mean Max 1h Max 24h
12016 Windsor West College Ave./South St. 8469 0 0 0 0 0 3 0.15 26 4
14111 Sarnia 700 Christina St. N. 7747 0 0 0 0 0 1 0.07 2 1
29000 Hamilton Downtown Elgin St./Kelly St. 8726 0 0 0 0 0 1 0.03 4 1
71078 Sault Ste. Marie Sault College 8724 0 0 0 0 0 1 0.05 7 1

10-year trends

10-year trend for nitric oxide (NO)

Annual mean (ppb)

ID City/Town 2011 2012 2013 2014 2015 2016 2017 2018 2019 2020 Change
over
10 year
(%)		 Trend
12008 Windsor Downtown 4.5 4.7 3.7 4.0 3.5 3.1 3.3 3.2 2.7 1.7 -39.0 SSS
12016 Windsor West 3.8 4.6 3.6 3.8 4.2 2.9 2.6 2.6 3.1 1.7 -38.7 SSS
13001 Chatham 1.9 1.8 1.6 1.5 1.7 1.4 1.9 1.8 1.4 1.5 -3.4 Non-SSS
14111 Sarnia 3.1 2.1 1.7 1.9 2.4 INS 1.5 1.8 1.7 1.6 -14.1 SSS
15020 Grand Bend 0.3 0.3 1.0 0.2 0.3 0.5 0.3 0.2 0.3 0.4 11.5 Non-SSS
15026 London 3.3 4.2 1.4 1.3 1.4 1.0 1.0 0.8 0.9 0.7 -52.3 SSS
21005 Brantford 1.2 1.1 1.2 0.9 1.3 0.8 0.8 1.0 0.9 0.8 -10.2 Non-SSS
26060 Kitchener 2.0 2.1 1.6 1.6 1.6 1.3 1.0 0.9 1.2 0.7 -28.4 SSS
27067 St. Catharines 2.3 2.5 2.2 1.7 2.1 1.5 1.2 0.9 1.2 0.9 -51.9 SSS
28028 Guelph 2.3 2.2 1.1 1.2 1.3 1.1 1.1 1.2 0.9 0.8 -37.0 SSS
29000 Hamilton Downtown 4.8 4.6 4.3 3.9 1.3 4.2 3.9 3.9 4.0 2.9 -18.3 SSS
29118 Hamilton West 6.4 6.3 5.4 5.9 5.1 6.2 3.9 4.2 4.2 3.2 -42.1 SSS
29214 Hamilton Mountain 2.3 1.9 2.0 2.0 1.8 1.2 1.2 1.2 1.8 1.4 -32.1 SSS
33003 Toronto East 7.6 6.6 5.7 6.2 5.8 5.4 4.4 3.1 3.4 2.3 -51.1 SSS
34021 Toronto North 6.2 5.0 4.1 4.3 3.9 3.5 3.0 2.5 2.7 2.1 -44.7 SSS
35125 Toronto West 12.4 11.3 8.6 9.5 9.2 8.2 7.7 6.7 7.5 5.2 -36.5 SSS
44008 Burlington 4.6 4.6 4.6 4.6 3.9 3.9 3.4 2.7 3.0 2.3 -44.5 SSS
44017 Oakville 2.7 3.4 2.1 3.4 2.7 1.8 1.7 1.8 1.8 1.3 -38.4 SSS
44029 Milton 4.6 4.8 2.8 3.1 3.5 4.2 2.3 3.6 3.6 2.7 -9.2 SSS
45027 Oshawa 2.3 2.1 1.5 2.0 2.3 2.5 2.4 0.9 0.9 0.9 -31.4 SSS
46090 Brampton 4.6 4.4 4.6 4.0 3.8 3.4 2.2 2.2 2.2 1.4 -49.7 SSS
46108 Mississauga 4.1 3.8 3.1 2.9 3.1 3.6 2.0 1.6 2.6 1.4 -39.0 SSS
47045 Barrie 3.8 3.2 3.2 3.7 3.5 3.7 2.6 1.8 2.2 1.4 -55.3 SSS
48006 Newmarket 2.2 2.0 1.5 1.4 1.7 1.6 1.4 1.3 1.3 0.8 -39.6 SSS
49005 Parry Sound 0.9 0.5 0.5 0.6 0.8 0.6 0.5 0.5 0.7 0.4 -12.5 Non-SSS
51001 Ottawa Downtown 1.8 2.4 2.1 1.9 2.0 1.7 1.5 1.7 1.6 1.4 -17.0 SSS
52023 Kingston 0.5 0.4 0.2 0.8 0.9 0.7 0.6 0.6 0.6 0.7 21.6 SSS
54012 Belleville 2.3 1.6 1.7 1.2 1.5 1.8 1.1 1.0 1.3 1.4 -19.5 SSS
56051 Cornwall 1.9 2.2 1.9 1.5 1.8 2.1 1.2 1.4 1.5 1.2 -11.5 SSS
59006 Peterborough 2.2 1.8 1.7 1.8 1.5 1.3 1.2 0.9 1.2 1.0 -41.2 SSS
63203 Thunder Bay 5.9 5.1 4.7 4.2 5.2 3.8 4.1 3.8 3.8 3.4 -23.7 SSS
71078 Sault Ste. Marie 2.0 1.7 1.3 2.0 1.7 1.0 1.3 1.2 1.5 1.6 -29.3 SSS
75010 North Bay 4.0 2.9 2.5 2.6 2.1 2.0 1.6 1.7 1.8 1.4 -41.1 SSS
77233 Sudbury N/A N/A 2.9 3.3 2.9 3.3 2.5 2.3 2.8 2.4 -22.9 SSS

Notes:

  • N/A indicates data not available.
  • INS indicates there was insufficient data to calculate a valid annual mean.
  • Station 14111 replaced station 14064 as the Sarnia site in 2016.
  • Station 15026 replaced station 15025 as the London site in 2013.
  • Station 29214 replaced station 29114 as the Hamilton Mountain site in 2019.
  • Station 34021 replaced station 34020 as the Toronto North site in 2017.
  • Station 44029 was operated by the Halton Region prior to 2019.
  • Station 45027 replaced station 45026 as the Oshawa site in 2018.
  • Station 46090 replaced station 46089 as the Brampton site in 2017.
  • Station 52023 replaced station 52022 as the Kingston site in 2014.
  • SSS - Significant Sen's Slope (significant trend detected).
  • Non-SSS - Non-Significant Sen's Slope (significant trend not detected).

10-year trend for nitrogen dioxide (NO2)

Annual mean (ppb)

ID City/Town 2011 2012 2013 2014 2015 2016 2017 2018 2019 2020 Change
over
10 year
(%)		 Trend
12008 Windsor Downtown 14.5 13.2 12.4 14.0 12.7 11.4 11.1 11.0 10.9 9.0 -26.9 SSS
12016 Windsor West 12.9 11.4 11.5 11.8 11.4 10.6 9.9 8.8 10.0 8.1 -31.3 SSS
13001 Chatham 6.6 5.7 6.0 6.8 6.8 5.4 6.1 5.1 5.8 5.1 -17.3 SSS
14111 Sarnia 8.6 8.6 8.1 9.0 9.3 INS 7.3 7.6 6.8 5.9 -22.9 SSS
15020 Grand Bend 3.6 3.6 4.4 3.1 3.4 2.8 3.0 3.3 2.5 2.3 -31.6 SSS
15026 London 8.3 6.3 6.4 6.9 6.6 5.4 5.8 5.4 5.8 4.5 -25.5 SSS
21005 Brantford 6.1 5.4 4.8 5.5 5.5 4.8 4.4 5.2 5.6 4.3 -11.6 SSS
26060 Kitchener 7.7 7.1 6.7 7.0 6.8 6.2 5.8 5.8 6.3 4.9 -22.5 SSS
27067 St. Catharines 8.5 8.1 7.7 7.3 7.3 6.6 6.6 6.0 6.0 5.3 -34.5 SSS
28028 Guelph 7.3 6.5 6.6 7.1 6.3 6.2 5.9 5.9 5.4 4.9 -24.5 SSS
29000 Hamilton Downtown 13.5 11.9 12.4 12.4 12.2 11.9 11.9 11.6 12.5 9.9 -14.1 SSS
29118 Hamilton West 13.1 12.1 12.7 12.8 12.2 11.8 10.4 11.0 11.3 9.5 -22.3 SSS
29214 Hamilton Mountain 9.9 8.6 9.0 9.3 9.0 7.9 7.8 7.8 8.8 6.9 -19.5 SSS
33003 Toronto East 15.2 14.0 13.6 14.2 13.9 12.1 11.5 10.6 10.2 8.4 -41.0 SSS
34021 Toronto North 15.4 13.4 12.9 13.4 12.9 12.0 10.5 10.4 10.5 8.9 -35.6 SSS
35125 Toronto West 19.1 16.3 16.1 17.1 16.6 15.7 15.0 14.4 14.6 12.1 -26.6 SSS
44008 Burlington 11.8 11.0 11.0 10.9 10.4 10.2 9.7 9.4 9.6 8.2 -22.5 SSS
44017 Oakville 10.3 9.1 9.2 8.2 7.5 8.2 8.2 8.5 9.1 6.8 -20.1 SSS
44029 Milton 12.1 10.4 8.5 8.4 9.4 9.3 7.7 9.8 8.9 7.6 -16.7 SSS
45027 Oshawa 7.0 5.6 5.9 6.8 6.6 6.3 6.4 3.8 3.5 3.6 -36.3 SSS
46090 Brampton 11.3 10.4 9.1 10.6 9.9 9.7 8.3 8.1 8.6 6.8 -31.4 SSS
46108 Mississauga 10.6 9.6 9.5 9.2 9.2 8.6 8.0 7.2 8.4 6.7 -27.9 SSS
47045 Barrie 8.6 8.1 7.8 8.1 7.4 8.1 7.3 6.4 6.3 5.6 -27.4 SSS
48006 Newmarket 8.1 7.2 6.8 6.8 6.8 6.5 6.3 6.1 5.5 4.5 -32.5 SSS
49005 Parry Sound 3.6 3.3 2.9 3.3 3.2 2.9 2.7 2.9 2.6 2.4 -26.6 SSS
51001 Ottawa Downtown 7.9 7.8 7.9 7.4 7.4 6.9 7.1 7.3 6.7 5.9 -20.9 SSS
52023 Kingston 4.6 4.0 3.6 3.9 4.4 4.4 4.4 4.2 4.0 3.5 -12.4 SSS
54012 Belleville 6.3 4.7 4.7 4.5 4.8 5.1 4.3 3.7 4.2 3.5 -23.1 SSS
56051 Cornwall 6.5 6.1 6.2 5.6 5.3 5.5 5.0 5.1 5.0 4.6 -19.4 SSS
59006 Peterborough 4.3 3.7 5.0 5.3 5.1 4.5 4.7 4.5 3.9 4.1 -25.9 SSS
63203 Thunder Bay 8.6 7.3 7.3 7.8 7.5 7.1 6.7 7.5 6.7 6.1 -19.6 SSS
71078 Sault Ste. Marie 5.3 4.8 5.0 5.3 4.8 4.0 4.4 4.4 4.5 3.7 -25.5 SSS
75010 North Bay 7.4 6.1 5.8 5.6 5.6 4.7 4.6 4.9 5.1 4.3 -26.5 SSS
77233 Sudbury N/A N/A 7.2 7.3 7.2 7.0 6.8 6.5 6.9 6.3 -12.6 SSS

Notes:

  • N/A indicates data not available.
  • INS indicates there was insufficient data to calculate a valid annual mean.
  • Station 14111 replaced station 14064 as the Sarnia site in 2016.
  • Station 15026 replaced station 15025 as the London site in 2013.
  • Station 29214 replaced station 29114 as the Hamilton Mountain site in 2019.
  • Station 34021 replaced station 34020 as the Toronto North site in 2017.
  • Station 44029 was operated by the Halton Region prior to 2019.
  • Station 45027 replaced station 45026 as the Oshawa site in 2018.
  • Station 46090 replaced station 46089 as the Brampton site in 2017.
  • Station 52023 replaced station 52022 as the Kingston site in 2014.
  • SSS - Significant Sen's Slope (significant trend detected).

10-year trend for nitrogen oxides (NOx)

Annual mean (ppb)

ID City/Town 2011 2012 2013 2014 2015 2016 2017 2018 2019 2020 Change
over
10 year
(%)		 Trend
12008 Windsor Downtown 18.9 17.8 16.2 18.0 16.2 14.5 14.4 14.2 13.6 10.7 -31.1 SSS
12016 Windsor West 16.7 16.0 15.2 15.7 15.5 13.5 12.5 11.3 13.0 9.9 -34.2 SSS
13001 Chatham 8.4 7.5 7.7 8.2 8.5 6.8 8.0 6.9 7.2 6.6 -16.1 SSS
14111 Sarnia 11.7 10.7 9.8 10.9 11.7 INS 8.7 9.4 8.5 7.5 -23.3 SSS
15020 Grand Bend 4.0 3.9 5.4 3.4 3.8 3.3 3.4 3.4 2.7 2.7 -30.0 SSS
15026 London 11.6 10.5 7.8 8.3 8.0 6.5 6.8 6.2 6.6 5.2 -39.1 SSS
21005 Brantford 7.3 6.7 5.7 6.4 6.8 5.7 5.3 6.2 6.5 5.1 -10.6 SSS
26060 Kitchener 9.6 9.2 8.3 8.5 8.4 7.5 6.9 6.7 7.4 5.5 -25.6 SSS
27067 St. Catharines 10.9 10.6 9.9 9.1 9.4 8.2 7.9 6.8 7.1 6.2 -38.0 SSS
28028 Guleph 9.5 8.8 7.8 8.4 7.7 7.3 7.0 7.1 6.4 5.6 -28.3 SSS
29000 Hamilton Downtown 18.3 16.6 16.8 16.3 7.7 16.1 15.8 15.5 16.5 12.8 -17.1 SSS
29118 Hamilton West 19.5 18.4 18.1 18.7 17.3 17.9 14.2 15.2 16.5 12.6 -30.1 SSS
29214 Hamilton Mountain 12.2 10.5 11.0 11.3 10.9 9.2 9.1 8.9 15.4 8.3 -21.7 SSS
33003 Toronto East 22.8 20.6 19.4 20.4 19.7 17.5 15.8 13.7 13.7 10.7 -46.8 SSS
34021 Toronto North 21.5 18.5 17.0 17.7 16.9 15.4 13.5 12.8 13.2 11.0 -39.2 SSS
35125 Toronto West 31.5 27.6 24.7 26.5 25.7 23.8 22.7 21.1 22.1 17.2 -32.4 SSS
44008 Burlington 16.4 15.6 15.6 15.5 14.3 14.2 13.2 12.0 12.6 10.5 -29.9 SSS
44017 Oakville 13.0 12.6 11.2 11.6 10.1 10.1 9.9 10.4 10.9 8.0 -26.3 SSS
44029 Milton 16.7 15.3 11.8 12.0 13.2 13.5 10.0 13.4 12.5 10.3 -17.8 SSS
45027 Oshawa 9.2 7.8 7.4 8.8 8.9 8.8 8.8 4.7 4.4 4.5 -34.7 SSS
46090 Brampton 15.9 14.8 13.9 14.6 13.7 13.1 10.6 10.3 10.74 8.1 -38.6 SSS
46108 Mississauga 14.7 13.4 12.6 12.1 12.3 12.2 9.9 8.8 10.97 8.0 -33.9 SSS
47045 Barrie 12.4 11.3 11.0 11.8 10.9 11.9 9.9 8.3 8.52 6.9 -37.2 SSS
48006 Newmarket 10.3 9.2 8.4 8.2 8.5 8.1 7.8 7.4 6.78 5.2 -32.0 SSS
49005 Parry Sound 4.5 3.8 3.4 4.0 4.0 3.6 3.3 3.3 3.34 2.8 -24.2 SSS
51001 Ottawa Downtown 9.7 10.2 10.1 9.3 9.5 8.6 8.6 9.0 8.31 7.3 -22.6 SSS
52023 Kingston 5.3 4.6 3.8 4.8 5.3 5.2 4.9 4.7 4.55 4.1 -12.7 SSS
54012 Belleville 8.7 6.4 6.3 5.7 6.2 6.7 5.4 4.7 5.53 4.9 -22.1 SSS
56051 Cornwall 8.4 8.4 8.0 7.0 7.1 7.6 6.2 6.3 6.54 5.8 -20.2 SSS
59006 Peterborough 6.6 5.4 6.6 7.1 6.6 5.9 5.8 5.3 5.14 5.0 -27.9 SSS
63203 Thunder Bay 14.5 12.4 12.0 11.9 12.7 11 10.8 11.3 10.44 9.5 -20.7 SSS
71078 Sault Ste. Marie 7.2 6.4 6.3 7.3 6.6 5.1 5.8 5.6 5.95 5.2 -26.0 SSS
75010 North Bay 11.5 9.1 8.3 8.1 7.8 6.7 6.2 6.6 6.91 5.6 -31.6 SSS
77233 Sudbury N/A N/A 10.1 10.6 10.2 10.2 9.4 8.8 9.7 8.7 -15.8 SSS

Notes:

  • N/A indicates data not available.
  • INS indicates there was insufficient data to calculate a valid annual mean.
  • Station 14111 replaced station 14064 as the Sarnia site in 2016.
  • Station 15026 replaced station 15025 as the London site in 2013.
  • Station 29214 replaced station 29114 as the Hamilton Mountain site in 2019.
  • Station 34021 replaced station 34020 as the Toronto North site in 2017.
  • Station 44029 was operated by the Halton Region prior to 2019.
  • Station 45027 replaced station 45026 as the Oshawa site in 2018.
  • Station 46090 replaced station 46089 as the Brampton site in 2017.
  • Station 52023 replaced station 52022 as the Kingston site in 2014.
  • SSS - Significant Sen's Slope (significant trend detected).

10-year trend for fine particulate matter (PM2.5)

Annual mean (µg/m3)

ID City/Town 2011 2012 2013 2014 2015 2016 2017 2018 2019 2020 Change
over
10 year
(%)		 Trend
12008 Windsor Downtown 9.4 9.8 9.2 10.1 9.3 8.1 7.8 8.5 7.8 7.1 -25.6 SSS
12016 Windsor West 9.7 9.5 10.0 10.7 9.9 8.5 8.5 8.7 9.1 8.8 -14.0 SSS
13001 Chatham 8.2 7.5 8.1 8.6 8.1 6.6 6.4 6.8 6.8 6.7 -20.0 SSS
14111 Sarnia 12.9 12.7 8.5 9.0 8.4 INS 7.0 7.4 7.1 7.1 -36.1 SSS
15020 Grand Bend 7.6 7.4 7.3 8.1 7.7 6.0 5.1 5.6 5.4 4.8 -42.7 SSS
15026 London 7.7 8.1 9.1 8.8 8.3 7.1 7.0 7.3 6.7 6.5 -27.7 SSS
16015 Port Stanley 7.5 7.4 7.4 8.2 8.0 6.5 6.3 6.8 6.7 6.5 -18.4 SSS
18007 Tiverton 6.0 6.0 5.8 6.5 6.4 5.1 5.1 5.7 5.0 4.8 -21.9 SSS
21005 Brantford 8.2 7.8 8.5 9.2 8.7 7.3 7.2 7.7 7.4 6.7 -18.7 SSS
26060 Kitchener 7.7 7.7 8.7 9.3 8.8 7.3 7.0 7.4 7.2 6.6 -20.8 SSS
27067 St. Catharines 7.8 7.9 8.5 8.8 8.4 6.9 7.0 7.0 7.0 6.3 -22.7 SSS
28028 Guelph 7.4 7.4 8.1 8.9 8.4 6.9 6.8 7.4 7.1 6.9 -12.6 SSS
29000 Hamilton Downtown 10.0 10.2 10.1 10.8 10.2 8.2 8.5 9.2 8.8 8.1 -24.0 SSS
29118 Hamilton West 8.8 9.0 9.6 9.9 9.9 7.9 7.5 8.2 7.8 7.8 -21.5 SSS
29214 Hamilton Mountain 8.3 8.1 9.2 9.4 9.0 7.2 7.4 7.7 7.9 7.1 -21.8 SSS
33003 Toronto East 7.8 7.8 8.2 8.9 8.5 7.0 7.4 7.2 7.0 6.7 -17.4 SSS
34021 Toronto North 9.5 9.0 8.3 9.2 9.4 7.3 7.4 7.6 6.8 6.4 -29.5 SSS
35125 Toronto West 8.7 8.8 8.8 9.1 8.5 7.0 7.4 7.7 7.2 6.9 -24.9 SSS
44008 Burlington 7.8 8.0 8.7 9.6 9.4 7.6 7.0 7.2 7.0 6.4 -28.7 SSS
44017 Oakville 8.0 7.6 8.0 8.5 8.3 7.0 6.9 7.4 7.2 6.3 -18.1 SSS
44029 Milton 8.0 7.9 8.5 10.3 8.8 7.1 7.0 7.5 7.5 7.1 -16.2 SSS
45027 Oshawa 6.9 6.9 7.4 7.7 7.5 5.9 5.9 6.4 6.1 6.2 -20.3 SSS
46090 Brampton 7.6 7.2 8.5 8.9 8.4 6.8 7.0 7.3 6.8 6.7 -17.3 SSS
46108 Mississauga 7.7 7.5 7.9 8.7 8.5 7.2 6.8 7.3 7.0 6.6 -18.1 SSS
47045 Barrie 7.2 7.1 7.5 7.6 7.6 6.5 7.0 7.7 7.5 6.8 -4.5 Non-SSS
48006 Newmarket 6.9 7.1 7.3 7.3 7.1 6.0 5.9 6.4 5.9 5.9 -21.1 SSS
49005 Parry Sound 6.0 6.0 5.8 5.8 5.7 4.8 4.6 5.0 4.4 4.4 -32.7 SSS
49010 Dorset 5.4 5.3 5.4 5.3 5.6 4.6 4.6 4.9 4.1 4.5 -19.5 SSS
51001 Ottawa Downtown 6.3 6.2 7.0 7.0 6.9 5.9 5.9 5.9 5.9 6.0 -13.6 SSS
51010 Petawawa 4.5 4.8 4.8 4.7 4.8 4.4 4.1 3.6 3.8 4.2 -22.8 SSS
52023 Kingston 8.5 8.3 6.5 6.8 6.3 5.8 5.3 5.6 5.4 5.6 -31.1 SSS
54012 Belleville 6.2 6.5 6.9 6.8 6.6 5.5 5.8 6.4 6.1 6.3 -6.6 Non-SSS
56051 Cornwall 7.3 6.9 7.7 7.0 6.9 6.4 5.9 6.3 5.9 6.0 -22.5 SSS
59006 Peterborough 7.0 6.3 7.4 6.9 6.8 5.8 5.8 6.3 6.0 5.6 -19.5 SSS
63203 Thunder Bay 6.2 5.4 6.3 6.6 6.5 4.9 5.1 6.0 5.1 5.5 -16.6 SSS
71078 Sault Ste. Marie 5.7 5.6 5.6 6.0 5.9 4.9 5.0 5.5 4.8 4.5 -18.6 SSS
75010 North Bay 5.5 5.3 5.2 5.3 5.3 4.6 4.6 5.5 4.5 4.6 -17.7 SSS
77233 Sudbury 5.2 5.1 5.7 6.0 6.3 5.4 5.0 5.4 5.0 5.1 2.3 Non-SSS

Notes:

  • From 2011-2012, measurements were taken by TEOM sampler operated at 30°C with a Sample Equilibration System (SES).
  • As of 2013, measurements taken by Synchronized Hybrid Ambient Real-time Particulate (SHARP) 5030.
  • An approximate correction factor was applied to the TEOM data prior to 2013 to be comparable to SHARP measurements and generate an approximate 10-year trend.
  • INS indicates there was insufficient data in any one quarter to calculate a valid annual mean.
  • Station 14111 replaced station 14064 as the Sarnia site in 2016.
  • Station 15026 replaced station 15025 as the London site in 2013.
  • Station 29214 replaced station 29114 as the Hamilton Mountain site in 2019.
  • Station 34021 replaced station 34020 as the Toronto North site in 2017.
  • Station 44029 was operated by the Halton Region prior to 2019.
  • Station 45027 replaced station 45026 as the Oshawa site in 2018.
  • Station 46090 replaced station 46089 as the Brampton site in 2017.
  • Station 52023 replaced station 52022 as the Kingston site in 2014.
  • Station 77233 replaced station 77219 as the Sudbury site in 2013.
  • SSS - Significant Sen's Slope (significant trend detected).
  • Non-SSS - Non-Significant Sen's Slope (significant trend not detected).

10-year trend for ground-level ozone (O3) 1h maximum

1h Maximum (ppb)
O3 1h AAQC: 80 ppb

ID City/Town 2011 2012 2013 2014 2015 2016 2017 2018 2019 2020 Change
over
10 year
(%)		 Trend
12008 Windsor Downtown 100 128 89 78 89 95 78 89 82 81 -19.0 Non-SSS
12016 Windsor West 101 128 87 86 87 95 82 90 80 83 -14.0 SSS
13001 Chatham 92 104 85 78 79 84 90 78 76 77 -16.3 SSS
14111 Sarnia 94 101 83 79 83 83 80 101 87 82 -1.9 Non-SSS
15020 Grand Bend 115 124 86 90 87 91 82 100 85 93 -15.7 Non-SSS
15026 London 83 88 82 82 77 82 78 76 70 77 -14.5 SSS
16015 Port Stanley 94 104 85 87 86 84 90 86 77 76 -19.1 SSS
18007 Tiverton 89 93 92 86 83 85 82 104 81 75 -15.2 SSS
21005 Brantford 94 88 74 80 79 84 74 76 74 74 -16.8 SSS
26060 Kitchener 87 89 72 76 76 81 75 75 77 74 -5.2 Non-SSS
27067 St. Catharines 83 98 96 70 73 80 73 75 70 75 -17.6 Non-SSS
28028 Guelph 94 94 73 79 79 82 76 78 74 70 -19.1 SSS
29000 Hamilton Downtown 92 88 86 74 74 78 73 77 65 77 -21.0 SSS
29118 Hamilton West 88 85 78 70 71 78 74 76 65 76 -15.3 Non-SSS
29214 Hamilton Mountain 95 91 86 79 79 76 81 80 70 79 -18.9 SSS
33003 Toronto East 82 89 87 73 91 99 82 72 67 77 -15.7 Non-SSS
34021 Toronto North 85 92 87 82 90 85 82 83 77 95 -7.1 Non-SSS
35125 Toronto West 87 94 83 72 82 79 82 76 77 81 -12.9 SSS
44008 Burlington 85 91 92 73 84 80 88 83 74 86 -6.6 Non-SSS
44017 Oakville 95 96 101 72 80 74 84 82 71 81 -17.8 Non-SSS
44029 Milton 93 94 93 80 80 79 74 81 77 77 -19.4 SSS
45027 Oshawa 85 92 96 73 73 81 86 76 66 88 -12.7 Non-SSS
46090 Brampton 88 92 84 80 84 79 75 83 72 83 -16.4 SSS
46108 Mississauga 87 81 83 76 79 79 78 79 65 80 -8.0 Non-SSS
47045 Barrie 67 91 73 68 80 79 75 72 75 70 -5.8 Non-SSS
48006 Newmarket 84 105 72 87 92 94 85 91 88 87 1.8 Non-SSS
49005 Parry Sound 81 94 77 74 86 74 74 80 68 73 -15.6 SSS
49010 Dorset 72 82 69 79 78 74 69 77 64 66 -12.5 SSS
51001 Ottawa Downtown 66 76 67 64 69 73 71 72 57 64 -6.8 Non-SSS
51010 Petawawa 67 77 69 68 70 68 65 66 58 63 -13.4 SSS
52023 Kingston 80 92 79 81 74 82 94 78 68 72 -16.9 Non-SSS
54012 Belleville 86 87 92 80 77 96 86 85 73 81 -10.5 Non-SSS
56051 Cornwall 72 76 73 70 69 74 72 68 58 62 -16.7 SSS
59006 Peterborough 86 90 74 74 78 85 80 86 68 87 0.0 Non-SSS
63203 Thunder Bay 60 74 63 70 62 62 51 63 56 56 -22.5 Non-SSS
71078 Sault Ste. Marie 80 82 66 73 75 80 70 69 61 77 -11.3 Non-SSS
75010 North Bay 74 82 72 71 70 78 69 63 63 74 -12.2 SSS
77233 Sudbury 67 84 76 73 67 80 69 70 75 62 -13.4 Non-SSS

Notes:

  • Station 14111 replaced station 14064 as the Sarnia site in 2016.
  • Station 15026 replaced station 15025 as the London site in 2013.
  • Station 29214 replaced station 29114 as the Hamilton Mountain site in 2019.
  • Station 34021 replaced station 34020 as the Toronto North site in 2017.
  • Station 44029 was operated by the Halton Region prior to 2019.
  • Station 45027 replaced station 45026 as the Oshawa site in 2018.
  • Station 46090 replaced station 46089 as the Brampton site in 2017.
  • Station 52023 replaced station 52022 as the Kingston site in 2014.
  • Station 77233 replaced station 77219 as the Sudbury site in 2013.
  • SSS - Significant Sen's Slope (significant trend detected).
  • Non-SSS - Non-Significant Sen's Slope (significant trend not detected).

10-year trend for ground-level ozone (O3)

Annual mean (ppb)

ID City/Town 2011 2012 2013 2014 2015 2016 2017 2018 2019 2020 Change
over
10 year
(%)		 Trend
12008 Windsor Downtown 27.2 28.0 26.9 26.0 27.0 27.7 27.3 26.9 26.6 27.3 0.9 Non-SSS
12016 Windsor West 26.4 28.0 26.7 27.2 26.5 27.7 27.0 27.0 27.3 26.0 1.2 Non-SSS
13001 Chatham 29.7 29.5 29.6 29.3 29.6 29.6 29.5 28.7 29.2 29.1 -1.9 Non-SSS
14111 Sarnia 29.7 29.7 28.6 27.1 27.8 28.8 28.4 29.0 29.2 26.7 -1.2 Non-SSS
15020 Grand Bend 32.8 33.2 32.3 31.0 30.4 30.7 31.0 31.5 31.6 30.9 -4.0 SSS
15026 London 26.8 27.7 28.7 28.1 27.9 28.2 28.1 27.6 26.8 27.7 1.7 Non-SSS
16015 Port Stanley 32.8 33.1 33.9 32.3 32.8 32.9 33.0 32.3 32.3 30.9 -4.7 SSS
18007 Tiverton 32.1 32.0 32.4 31.8 32.5 33.1 32.4 32.3 31.1 30.5 -2.3 Non-SSS
21005 Brantford 28.7 28.8 29.0 29.4 28.9 29.5 28.3 28.3 27.5 28.0 -4.2 SSS
26060 Kitchener 27.6 28.0 28.0 27.3 27.9 28.8 28.1 27.7 27.2 27.7 -0.4 Non-SSS
27067 St. Catharines 28.0 28.7 28.6 28.5 28.6 29.8 28.1 28.5 28.4 30.2 4.7 SSS
28028 Guelph 28.9 28.8 29.0 27.8 27.7 28.7 28.4 28.9 26.3 27.0 -4.1 SSS
29000 Hamilton Downtown 25.4 25.7 25.0 25.3 25.9 26.7 25.6 25.6 24.4 26.3 2.4 Non-SSS
29118 Hamilton West 24.2 24.2 24.4 22.7 23.9 24.4 25.0 25.5 23.6 25.2 4.0 Non-SSS
29214 Hamilton Mountain 28.8 30.2 29.5 29.1 29.4 29.5 29.1 29.3 27.5 29.3 -2.2 Non-SSS
33003 Toronto East 23.3 24.6 24.1 23.4 23.5 25.5 24.4 25.2 24.6 26.1 10.0 SSS
34021 Toronto North 23.6 25.7 25.3 25.3 25.7 25.9 24.0 25.5 24.1 26.0 4.3 Non-SSS
35125 Toronto West 20.1 21.5 21.5 21.1 21.3 22.1 22.1 22.3 21.8 23.4 12.6 SSS
44008 Burlington 25.9 26.7 26.4 25.5 26.5 27.6 27.1 27.6 26.6 28.3 9.1 SSS
44017 Oakville 26.8 27.7 28.3 27.2 27.4 27.1 27.4 28.7 27.1 28.0 3.2 Non-SSS
44029 Milton 25.7 26.5 27.6 27.1 27.2 27.2 27.5 28.1 26.9 26.8 4.0 Non-SSS
45027 Oshawa 26.6 27.0 27.2 27.2 26.2 27.2 27.9 25.8 24.4 26.4 -4.2 SSS
46090 Brampton 26.1 26.6 26.7 26.5 26.5 27.1 27.2 28.6 26.5 28.4 8.5 SSS
46108 Mississauga 24.1 25.6 25.2 25.4 25.4 26.0 26.2 26.1 24.5 25.6 3.7 Non-SSS
47045 Barrie 25.3 26.3 25.5 25.6 25.4 25.9 25.9 27.5 25.7 25.9 3.2 Non-SSS
48006 Newmarket 27.8 29.4 28.7 28.6 28.5 28.6 27.9 29.8 27.8 28.5 2.4 Non-SSS
49005 Parry Sound 29.7 30.1 30.4 29.6 30.4 29.6 29.7 30.8 29.8 29.9 1.5 Non-SSS
49010 Dorset 27.0 28.0 28.1 27.7 27.0 27.4 26.9 28.2 27.5 27.1 1.0 Non-SSS
51001 Ottawa Downtown 24.2 26.0 25.6 24.8 25.6 25.6 25.5 26.4 25.9 25.2 4.4 Non-SSS
51010 Petawawa 26.7 27.7 27.6 26.8 26.7 26.4 25.8 27.3 27.3 26.9 -0.3 Non-SSS
52023 Kingston 30.3 32.7 30.3 31.4 30.3 30.5 30.4 30.5 29.9 30.1 -3.2 Non-SSS
54012 Belleville 27.9 28.0 29.2 29.6 29.6 30.5 30.2 29.9 29.6 29.7 7.6 SSS
56051 Cornwall 26.1 27.1 26.9 27.3 27.9 27.1 27.2 27.6 26.9 26.4 0.3 Non-SSS
59006 Peterborough 27.9 29.1 28.6 29.2 29.3 29.7 28.9 29.7 28.3 27.6 0.6 Non-SSS
63203 Thunder Bay 25.2 25.0 26.3 23.4 24.0 23.2 23.4 24.3 23.7 22.9 -9.0 SSS
71078 Sault Ste. Marie 27.8 28.8 28.9 28.4 27.8 27.3 28.1 29.7 28.1 28.2 0.6 Non-SSS
75010 North Bay 26.7 26.1 27.4 26.7 27.0 26.4 26.4 26.0 26.4 26.2 -1.8 Non-SSS
77233 Sudbury 28.7 28.5 27.2 26.3 25.7 25.1 25.9 27.1 26.3 24.8 -9.0 SSS

Notes:

  • Station 14111 replaced station 14064 as the Sarnia site in 2016.
  • Station 15026 replaced station 15025 as the London site in 2013.
  • Station 29214 replaced station 29114 as the Hamilton Mountain site in 2019.
  • Station 34021 replaced station 34020 as the Toronto North site in 2017.
  • Station 44029 was operated by the Halton Region prior to 2019.
  • Station 45027 replaced station 45026 as the Oshawa site in 2018.
  • Station 46090 replaced station 46089 as the Brampton site in 2017.
  • Station 52023 replaced station 52022 as the Kingston site in 2014.
  • Station 77233 replaced station 77219 as the Sudbury site in 2013.
  • SSS - Significant Sen's Slope (significant trend detected).
  • Non-SSS - Non-Significant Sen's Slope (significant trend not detected).

10-year trend for ground-level ozone (O3) summer means (May - September)

Summer mean (ppb)

ID City/Town 2011 2012 2013 2014 2015 2016 2017 2018 2019 2020 Change
over
10 year
(%)		 Trend
12008 Windsor Downtown 33.8 36.8 32.5 30.9 33.3 33.4 32.8 33.7 31.4 32.7 -3.3 Non-SSS
12016 Windsor West 31.9 35.7 30.9 30.9 31.8 33.0 31.8 32.4 31.2 30.6 -2.7 Non-SSS
13001 Chatham 34.4 36.6 34.2 32.4 34.4 32.9 33.1 32.1 31.9 32.5 -8.5 SSS
14111 Sarnia 32.9 36.6 32.0 29.4 31.1 32.1 32.0 34.0 31.5 30.1 -4.2 Non-SSS
15020 Grand Bend 33.9 38.9 33.1 31.5 32.3 32.0 32.1 32.7 31.7 31.7 -6.1 SSS
15026 London 30.7 34.4 30.9 29.5 31.0 30.4 29.8 30.5 27.4 29.1 -9.7 SSS
16015 Port Stanley 35.5 38.4 36.9 33.7 35.6 35.2 35.0 35.3 33.7 32.8 -12.1 SSS
18007 Tiverton 31.7 36.0 32.5 30.8 33.3 34.1 32.2 32.9 29.7 30.5 -8.2 Non-SSS
21005 Brantford 31.1 33.5 30.1 29.9 31.2 32.2 29.4 30.4 28.3 29.5 -8.6 Non-SSS
26060 Kitchener 30.2 33.5 29.8 28.5 30.2 31.8 29.8 30.6 29.2 29.6 -2.7 Non-SSS
27067 St. Catharines 31.2 35.0 31.2 29.5 31.7 33.2 29.8 31.3 29.7 32.6 -1.3 Non-SSS
28028 Guelph 31.3 34.5 30.4 28.9 30.2 31.2 29.6 31.7 27.3 29.0 -8.1 Non-SSS
29000 Hamilton Downtown 28.7 32.4 28.4 27.5 29.5 30.6 27.8 29.7 26.1 29.4 -4.9 Non-SSS
29118 Hamilton West 26.2 29.2 26.4 22.7 26.5 27.1 26.8 28.5 24.4 27.7 3.6 Non-SSS
29214 Hamilton Mountain 32.3 37.4 32.5 31.6 33.9 33.2 31.5 34.0 29.6 32.3 -7.0 Non-SSS
33003 Toronto East 27.4 30.6 27.1 25.9 27.7 29.7 26.0 29.2 26.0 28.8 -4.1 Non-SSS
34021 Toronto North 27.5 32.7 29.4 28.6 30.7 30.7 26.3 30.4 25.9 29.3 -6.5 Non-SSS
35125 Toronto West 23.6 27.5 24.4 23.5 25.0 25.9 24.3 26.3 24.3 25.9 6.5 Non-SSS
44008 Burlington 29.2 32.5 29.2 27.4 30.1 30.5 29.0 31.8 28.8 31.2 5.6 Non-SSS
44017 Oakville 29.9 34.2 30.6 28.3 30.2 29.9 29.5 32.4 28.8 30.4 -4.4 Non-SSS
44029 Milton 29.2 32.2 30.6 28.2 30.4 30.6 29.6 34.3 28.9 28.6 -7.7 Non-SSS
45027 Oshawa 28.5 31.1 28.3 27.9 28.9 29.4 28.6 26.6 24.4 27.4 -10.8 Non-SSS
46090 Brampton 29.3 32.7 29.5 28.9 30.3 31.2 29.5 32.7 28.2 31.0 1.3 Non-SSS
46108 Mississauga 26.7 30.4 26.5 26.5 28.0 28.5 27.2 28.3 24.9 27.0 -2.8 Non-SSS
47045 Barrie 26.2 29.7 25.6 25.4 26.8 27.4 25.6 29.0 24.7 25.8 -3.8 Non-SSS
48006 Newmarket 30.5 34.2 30.3 29.4 31.2 31.7 29.0 33.2 28.4 30.1 -5.8 Non-SSS
49005 Parry Sound 28.7 32.8 30.1 28.2 31.4 28.9 27.7 30.9 27.8 28.5 -5.0 Non-SSS
49010 Dorset 23.8 28.3 25.3 24.4 24.6 25.1 23.0 25.8 23.9 23.7 -5.8 Non-SSS
51001 Ottawa Downtown 25.1 29.3 26.5 24.6 27.8 27.5 25.3 27.6 25.6 25.7 -2.9 Non-SSS
51010 Petawawa 22.8 28.1 24.5 22.9 24.4 23.4 21.1 23.7 22.9 22.7 -10.1 Non-SSS
52023 Kingston 32.0 38.5 32.4 32.7 32.2 33.3 30.9 33.1 30.0 31.3 -6.5 Non-SSS
54012 Belleville 29.9 32.7 30.6 30.4 33.2 33.7 30.9 32.4 30.0 31.0 1.7 Non-SSS
56051 Cornwall 26.7 30.7 28.1 27.0 29.7 28.7 27.1 29.4 26.1 26.3 -7.1 Non-SSS
59006 Peterborough 29.8 34.2 29.5 30.0 31.5 32.3 29.2 32.2 28.1 28.4 -6.3 Non-SSS
63203 Thunder Bay 24.2 25.3 24.7 22.7 23.6 22.0 20.4 22.1 21.8 21.3 -17.7 SSS
71078 Sault Ste. Marie 26.4 30.3 28.2 27.4 28.1 26.3 26.3 29.1 26.2 26.4 -5.4 Non-SSS
75010 North Bay 26.3 28.5 26.9 26.2 27.8 26.4 24.7 26.3 25.7 24.4 -8.9 SSS
77233 Sudbury 26.9 29.8 28.0 27.0 27.7 26.6 25.8 28.8 25.9 23.7 -12.3 Non-SSS

Notes:

  • Station 14111 replaced station 14064 as the Sarnia site in 2016.
  • Station 15026 replaced station 15025 as the London site in 2013.
  • Station 29214 replaced station 29114 as the Hamilton Mountain site in 2019.
  • Station 34021 replaced station 34020 as the Toronto North site in 2017.
  • Station 44029 was operated by the Halton Region prior to 2019.
  • Station 45027 replaced station 45026 as the Oshawa site in 2018.
  • Station 46090 replaced station 46089 as the Brampton site in 2017.
  • Station 52023 replaced station 52022 as the Kingston site in 2014.
  • Station 77233 replaced station 77219 as the Sudbury site in 2013.
  • SSS - Significant Sen's Slope (significant trend detected).
  • Non-SSS - Non-Significant Sen's Slope (significant trend not detected).

10-year trend for ground-level ozone (O3) winter means (January-April, October-December)

Winter mean (ppb)

ID City/Town 2011 2012 2013 2014 2015 2016 2017 2018 2019 2020 Change
over
10 year
(%)		 Trend
12008 Windsor Downtown 22.5 21.7 22.8 22.8 22.4 23.6 23.3 22.4 23.1 23.5 4.6 Non-SSS
12016 Windsor West 22.5 22.3 23.4 24.5 22.7 23.9 23.6 23.1 24.4 22.8 3.3 Non-SSS
13001 Chatham 26.7 24.3 26.2 27.1 26.3 27.2 26.8 26.2 27.4 26.7 2.1 Non-SSS
14111 Sarnia 27.4 24.7 26.2 25.4 25.4 INS 26.0 25.4 27.6 24.3 -1.9 Non-SSS
15020 Grand Bend 32.1 29.1 31.8 30.6 29.1 29.8 30.2 30.7 31.6 30.5 -0.6 Non-SSS
15026 London 24.2 22.9 26.9 27.1 25.8 26.6 26.9 25.6 26.4 26.7 7.1 Non-SSS
16015 Port Stanley 31.0 29.3 31.8 31.3 31.2 31.2 31.5 30.2 31.4 29.6 -1.8 Non-SSS
18007 Tiverton 32.2 29.2 32.4 32.7 31.9 32.4 32.6 31.9 32.1 30.6 -0.9 Non-SSS
21005 Brantford 27.1 25.4 28.3 28.8 27.2 27.7 27.5 26.7 26.9 27.0 -1.9 Non-SSS
26060 Kitchener 25.7 24.0 26.7 26.5 26.1 26.6 27.1 25.6 25.8 26.4 2.3 Non-SSS
27067 St. Catharines 25.8 24.1 26.8 27.9 26.3 27.2 27.0 26.4 27.5 28.5 8.8 SSS
28028 Guelph 27.2 24.8 28.0 27.0 26.0 26.8 27.5 26.9 25.7 25.6 -3.3 Non-SSS
29000 Hamilton Downtown 23.1 20.9 22.5 23.7 23.3 23.9 24.2 22.6 23.2 24.1 6.3 Non-SSS
29118 Hamilton West 22.7 20.6 23.0 22.8 22.1 22.5 23.7 23.3 23.0 23.5 4.7 SSS
29214 Hamilton Mountain 26.3 25.0 27.3 27.3 26.3 26.8 27.4 25.9 25.9 27.2 1.2 Non-SSS
33003 Toronto East 20.4 20.3 22.0 21.6 20.5 22.5 23.3 22.4 23.5 24.2 18.6 SSS
34021 Toronto North 20.8 20.7 22.3 22.8 22.1 22.6 22.3 22.0 22.8 23.7 10.2 SSS
35125 Toronto West 17.7 17.2 19.5 19.4 18.6 19.4 20.5 19.4 20.1 21.6 18.5 SSS
44008 Burlington 23.5 22.5 24.4 24.1 23.8 25.6 25.7 24.7 25.2 26.2 12.8 SSS
44017 Oakville 24.7 23.1 26.6 26.5 25.3 25.1 25.9 26.0 26.0 26.3 5.9 Non-SSS
44029 Milton 23.3 22.2 25.5 26.3 24.9 24.7 25.9 24.9 25.5 25.6 8.5 Non-SSS
45027 Oshawa 25.2 24.1 26.4 26.7 24.3 25.6 27.3 25.4 24.5 25.7 2.2 Non-SSS
46090 Brampton 23.8 22.2 24.6 24.8 23.8 24.1 25.6 25.6 25.3 26.5 11.1 SSS
46108 Mississauga 22.5 22.2 24.3 24.7 23.6 24.2 25.5 24.6 24.2 24.7 9.7 Non-SSS
47045 Barrie 24.7 23.9 25.5 25.8 24.4 24.8 26.3 26.5 26.4 26.1 7.1 SSS
48006 Newmarket 25.8 26.0 27.5 28.1 26.6 26.3 27.2 27.3 27.3 27.5 6.0 Non-SSS
49005 Parry Sound 30.4 28.1 30.6 30.6 29.8 30.0 31.1 30.7 31.3 31.0 3.5 SSS
49010 Dorset 29.5 27.7 30.1 30.1 28.8 29.0 29.6 30.0 30.1 29.5 2.4 Non-SSS
51001 Ottawa Downtown 23.6 23.5 24.9 25.1 24.0 24.3 25.6 25.5 26.2 24.9 7.4 SSS
51010 Petawawa 29.5 27.5 29.9 29.6 28.5 28.6 29.3 29.8 30.4 30.0 3.9 Non-SSS
52023 Kingston 29.0 28.6 28.8 30.4 28.9 28.5 30.2 28.6 29.9 29.2 0.8 Non-SSS
54012 Belleville 26.4 24.6 28.2 29.1 27.0 28.2 29.7 28.1 29.3 28.7 11.5 Non-SSS
56051 Cornwall 25.7 24.2 25.7 27.6 26.6 26.0 27.4 26.3 27.5 26.5 4.1 Non-SSS
59006 Peterborough 26.6 25.5 28.0 28.6 27.7 27.8 28.7 27.9 28.5 27.3 2.9 Non-SSS
63203 Thunder Bay 26.1 24.7 27.4 23.8 24.2 24.2 25.6 25.9 25.1 24.1 -2.4 Non-SSS
71078 Sault Ste. Marie 28.9 27.6 29.4 29.2 27.7 28.0 29.5 30.2 29.5 29.6 3.2 SSS
75010 North Bay 27.0 24.4 27.8 27.1 26.4 26.4 27.6 25.9 26.9 27.4 1.2 Non-SSS
77233 Sudbury 30.0 27.6 26.6 25.8 24.3 24.0 26.1 26.0 26.7 25.7 -4.4 Non-SSS

Notes:

  • Station 14111 replaced station 14064 as the Sarnia site in 2016.
  • Station 15026 replaced station 15025 as the London site in 2013.
  • Station 29214 replaced station 29114 as the Hamilton Mountain site in 2019.
  • Station 34021 replaced station 34020 as the Toronto North site in 2017.
  • Station 44029 was operated by the Halton Region prior to 2019.
  • Station 45027 replaced station 45026 as the Oshawa site in 2018.
  • Station 46090 replaced station 46089 as the Brampton site in 2017.
  • Station 52023 replaced station 52022 as the Kingston site in 2014.
  • Station 77233 replaced station 77219 as the Sudbury site in 2013.
  • SSS - Significant Sen's Slope (significant trend detected).
  • Non-SSS - Non-Significant Sen's Slope (significant trend not detected).

10-year trend for sulphur dioxide (SO2)

Annual mean (ppb)
SO2 1y AAQC: 4 ppb

ID City/Town 2011 2012 2013 2014 2015 2016 2017 2018 2019 2020 Change
over
10 year
(%)		 Trend
12008 Windsor Downtown 3.5 2.8 2.4 2.4 1.9 1.1 1.0 0.6 0.4 0.3 -86.7 SSS
12016 Windsor West 3.4 2.8 2.6 2.8 1.9 1.4 0.9 0.7 0.8 0.8 -76.2 SSS
14111 Sarnia 5.3 4.1 3.8 3.5 3.2 INS 1.7 1.9 1.9 2.0 -50.4 SSS
29000 Hamilton Downtown 5.2 4.8 4.8 5.1 4.3 3.2 3.5 5.0 4.8 3.7 -19.9 SSS
29214 Hamilton Mountain 4.1 3.7 2.8 2.9 2.6 1.8 1.8 2.4 3.5 2.5 -29.2 SSS
35125 Toronto West 1.5 0.6 0.6 0.7 1.0 0.6 0.5 0.3 0.3 0.2 -52.2 SSS
44029 Milton 1.0 1.3 1.2 1.3 1.1 0.9 0.7 0.7 INS INS -34.6 SSS
51001 Ottawa Downtown 0.4 0.3 0.3 0.3 0.4 0 0.1 0.2 0.2 0.1 -25.0 SSS
71078 Sault Ste. Marie 0.8 0.6 0.8 0.8 0.8 0.6 0.7 0.8 0.7 0.6 -11.8 Non-SSS
77233 Sudbury 1.5 1.3 2.8 2.4 2.4 2.1 1.3 1.2 1.2 0.9 -60.0 SSS

Notes:

  • INS indicates there was insufficient data to calculate a valid annual mean.
  • Station 14111 replaced station 14064 as the Sarnia site in 2016.
  • Station 29214 replaced station 29114 as the Hamilton Mountain site in 2019.
  • Station 44029 was operated by the Halton Region prior to 2019.
  • SSS - Significant Sen's Slope (significant trend detected).
  • Non-SSS - Non-Significant Sen's Slope (significant trend not detected).

10-year trend for carbon monoxide (CO)

1h maximum (ppm)
CO 1h AAQC: 30 ppm

ID City/Town 2011 2012 2013 2014 2015 2016 2017 2018 2019 2020 Change
over
10 year
(%)		 Trend
12008 Windsor Downtown 3.8 2.1 1.9 1.8 1.9 2.3 2.6 1.9 2.3 1.2 -23.1 Non-SSS
29000 Hamilton Downtown 1.8 1.7 2.0 2.9 1.3 1.4 2.1 1.7 1.9 1.2 -19.7 Non-SSS
35125 Toronto West 1.4 1.4 1.4 1.6 1.3 1.7 1.2 0.9 1.5 1.6 6.5 Non-SSS
51001 Ottawa Downtown 1.5 0.9 0.9 0.8 0.8 0.9 0.7 1.0 0.7 0.9 -22.2 Non-SSS

Note:

  • Non-SSS - Non-Significant Sen's Slope (significant trend not detected).

10-year trend for benzene

Annual mean (µg/m3)
Benzene 1y AAQC: 0.45 µg/m3

ID City/Town 2010 2011 2012 2013 2014 2015 2016 2017 2018 2019 Change
over
10 year
(%)		 Trend
12016 Windsor West 0.687 INS 0.558 0.519 0.610 0.566 0.521 0.450 0.478 0.445 -28.9 SSS
14111 Sarnia 0.961 INS 0.900 0.820 1.007 1.191 0.689 0.604 0.574 0.419 -42.3 SSS
15026 London 0.490 INS 0.455 0.413 0.446 0.451 0.341 0.339 0.321 0.296 -39.5 SSS
26060 Kitchener 0.537 INS 0.479 N/A 0.483 0.548 0.395 0.446 0.355 0.290 -41.6 SSS
29000 Hamilton Downtown 1.060 INS 0.977 INS 0.899 1.092 0.675 0.569 0.639 0.568 -35.1 SSS
48006 Newmarket 0.416 N/A 0.371 0.406 0.422 0.425 0.328 0.385 INS 0.250 -32.4 SSS
51001 Ottawa Downtown 0.451 0.418 0.422 0.442 0.413 0.453 0.365 0.388 0.405 0.323 -20.7 SSS

Notes:

  • INS indicates there was insufficient data to calculate a valid annual mean.
  • N/A indicates data not available.
  • The 2016 average for Sarnia is derived from data from May to December 2016.
  • Station 14111 replaced station 14064 as the Sarnia site in 2016.
  • The 2018 average for Windsor West is derived from data from February to July, and October to December in 2018.
  • The 2018 average for Sarnia is derived from data from February to May, July, and October to December in 2018.
  • The 2018 average for Hamilton Downtown is derived from data from March to June, August, and October to December in 2018.
  • SSS - Significant Sen's Slope (significant trend detected).

10-year trend for toluene

Annual mean (µg/m3)

ID City/Town 2010 2011 2012 2013 2014 2015 2016 2017 2018 2019 Change
over
10 year
(%)		 Trend
12016 Windsor West 1.679 INS 1.392 1.017 1.542 1.248 1.272 0.972 1.131 0.797 -35.7 SSS
14111 Sarnia 2.037 INS 2.539 1.587 1.908 2.350 1.778 1.550 1.014 0.779 -41.1 SSS
15026 London 1.334 INS 1.408 0.887 0.839 1.013 0.727 0.633 0.657 0.491 -50.9 SSS
26060 Kitchener 1.477 INS 1.322 N/A 1.278 1.052 1.020 1.002 0.625 0.572 -47.7 SSS
29000 Hamilton Downtown 2.842 INS 2.067 INS 2.229 2.249 1.642 1.296 0.862 0.817 -47.2 SSS
48006 Newmarket 0.878 N/A 0.877 0.916 0.732 1.340 1.118 0.807 INS 0.418 -30.8 SSS
51001 Ottawa Downtown 1.212 0.929 0.899 0.975 0.741 0.982 0.902 0.826 0.704 0.618 -29.4 SSS

Notes:

  • INS indicates there was insufficient data to calculate a valid annual mean.
  • N/A indicates data not available.
  • The 2016 average for Sarnia is derived from data from May to December 2016.
  • Station 14111 replaced station 14064 as the Sarnia site in 2016.
  • The 2018 average for Windsor West is derived from data from February to July, and October to December in 2018.
  • The 2018 average for Sarnia is derived from data from February to May, July, and October to December in 2018.
  • The 2018 average for Hamilton Downtown is derived from data from March to June, August, and October to December in 2018.
  • SSS - Significant Sen's Slope (significant trend detected).

10-year trend for ethylbenzene

Annual mean (µg/m3)

ID City/Town 2010 2011 2012 2013 2014 2015 2016 2017 2018 2019 Change
over
10 year
(%)		 Trend
12016 Windsor West 0.275 INS 0.221 0.179 0.267 0.238 0.234 0.181 0.187 0.137 -37.4 SSS
14111 Sarnia 0.392 INS 0.278 0.255 0.253 0.362 0.282 0.211 0.235 0.118 -36.6 SSS
15026 London 0.190 INS 0.143 0.125 0.121 0.149 0.108 0.105 0.141 0.070 -43.5 SSS
26060 Kitchener 0.220 INS 0.162 N/A 0.167 0.168 0.159 0.164 0.109 0.079 -37.9 SSS
29000 Hamilton Downtown 0.278 INS 0.193 INS 0.192 0.210 0.186 0.187 0.129 0.126 -28.7 SSS
48006 Newmarket 0.154 N/A 0.115 0.134 0.125 0.249 0.215 0.130 INS 0.067 -29.4 SSS
51001 Ottawa Downtown 0.144 0.122 0.105 0.112 0.099 0.123 0.119 0.120 0.088 0.064 -24.9 SSS

Notes:

  • INS indicates there was insufficient data to calculate a valid annual mean.
  • N/A indicates data not available.
  • The 2016 average for Sarnia is derived from data from May to December 2016.
  • Station 14111 replaced station 14064 as the Sarnia site in 2016.
  • The 2018 average for Windsor West is derived from data from February to July, and October to December in 2018.
  • The 2018 average for Sarnia is derived from data from February to May, July, and October to December in 2018.
  • The 2018 average for Hamilton Downtown is derived from data from March to June, August, and October to December in 2018.
  • SSS - Significant Sen's Slope (significant trend detected).

10-year trend for m- and p-xylene

Annual mean (µg/m3)

ID City/Town 2010 2011 2012 2013 2014 2015 2016 2017 2018 2019 Change
over
10 year
(%)		 Trend
12016 Windsor West 0.818 INS 0.689 0.536 0.825 0.702 0.635 0.505 0.502 0.409 -41.9 SSS
14111 Sarnia 0.790 INS 0.676 0.510 0.629 0.850 0.495 0.499 0.563 0.256 -32.3 SSS
15026 London 0.500 INS 0.388 0.345 0.318 0.398 0.267 0.268 0.407 0.200 -38.2 SSS
26060 Kitchener 0.639 INS 0.478 N/A 0.469 0.464 0.434 0.451 0.276 0.223 -39.1 SSS
29000 Hamilton Downtown 0.842 INS 0.603 INS 0.594 0.621 0.518 0.532 0.359 0.398 -30.2 SSS
48006 Newmarket 0.437 N/A 0.333 0.362 0.334 0.582 0.484 0.350 INS 0.191 -33.6 SSS
51001 Ottawa Downtown 0.429 0.355 0.310 0.329 0.309 0.363 0.338 0.334 0.222 0.186 -30.6 SSS

Notes:

  • INS indicates there was insufficient data to calculate a valid annual mean.
  • N/A indicates data not available.
  • The 2016 average for Sarnia is derived from data from May to December 2016.
  • Station 14111 replaced station 14064 as the Sarnia site in 2016.
  • The 2018 average for Windsor West is derived from data from February to July, and October to December in 2018.
  • The 2018 average for Sarnia is derived from data from February to May, July, and October to December in 2018.
  • The 2018 average for Hamilton Downtown is derived from data from March to June, August, and October to December in 2018.
  • SSS - Significant Sen's Slope (significant trend detected).

10-year trend for o-xylene

Annual mean (µg/m3)

ID City/Town 2010 2011 2012 2013 2014 2015 2016 2017 2018 2019 Change
over
10 year
(%)		 Trend
12016 Windsor West 0.255 INS 0.228 0.184 0.283 0.239 0.232 0.190 0.184 0.147 -32.2 SSS
14111 Sarnia 0.262 INS 0.244 0.171 0.226 0.313 0.178 0.192 0.213 0.101 -30.2 SSS
15026 London 0.147 INS 0.126 0.118 0.113 0.146 0.103 0.103 0.148 0.074 -31.8 SSS
26060 Kitchener 0.188 INS 0.157 N/A 0.166 0.164 0.153 0.164 0.107 0.082 -40.9 SSS
29000 Hamilton Downtown 0.241 INS 0.195 INS 0.206 0.216 0.189 0.198 0.131 0.145 -18.5 SSS
48006 Newmarket 0.133 N/A 0.116 0.126 0.134 0.218 0.192 0.128 INS 0.068 -24.8 N-SSS
51001 Ottawa Downtown 0.147 0.128 0.118 0.118 0.111 0.136 0.127 0.132 0.089 0.078 -18.5 SSS

Notes:

  • INS indicates there was insufficient data to calculate a valid annual mean.
  • N/A indicates data not available.
  • The 2016 average for Sarnia is derived from data from May to December 2016.
  • Station 14111 replaced station 14064 as the Sarnia site in 2016.
  • The 2018 average for Windsor West is derived from data from February to July, and October to December in 2018.
  • The 2018 average for Sarnia is derived from data from February to May, July, and October to December in 2018.
  • The 2018 average for Hamilton Downtown is derived from data from March to June, August, and October to December in 2018.
  • SSS - Significant Sen's Slope (significant trend detected).
  • Non-SSS - Non-Significant Sen's Slope (significant trend not detected).

10-year trend for 1,3-butadiene

Annual mean (µg/m3)
1,3-butadiene 1y AAQC: 2.0 µg/m3

ID City/Town 2010 2011 2012 2013 2014 2015 2016 2017 2018 2019 Change
over
10 year
(%)		 Trend
12016 Windsor West 0.056 INS 0.048 0.036 0.042 0.035 0.032 0.034 0.028 0.028 -41.0 SSS
14111 Sarnia 0.167 INS 0.205 0.209 0.124 0.216 0.089 0.077 0.088 0.054 -46.8 SSS
15026 London 0.050 INS 0.040 0.023 0.025 0.026 0.020 0.035 0.025 0.025 -36.0 SSS
26060 Kitchener 0.056 INS 0.042 N/A 0.029 0.029 0.023 0.038 0.026 0.025 -35.1 SSS
29000 Hamilton Downtown 0.060 INS 0.046 INS 0.032 0.037 0.025 0.039 0.028 0.028 -31.5 SSS
48006 Newmarket 0.051 N/A 0.039 0.021 0.020 0.028 0.024 0.035 INS 0.025 -32.2 SSS
51001 Ottawa Downtown 0.052 0.041 0.040 0.035 0.026 0.030 0.027 0.037 0.032 0.027 -36.9 SSS

Notes:

  • INS indicates there was insufficient data to calculate a valid annual mean.
  • N/A indicates data not available.
  • The 2016 average for Sarnia is derived from data from May to December 2016.
  • Station 14111 replaced station 14064 as the Sarnia site in 2016.
  • The 2018 average for Windsor West is derived from data from February to July, and October to December in 2018.
  • The 2018 average for Sarnia is derived from data from February to May, July, and October to December in 2018.
  • The 2018 average for Hamilton Downtown is derived from data from March to June, August, and October to December in 2018.
  • SSS - Significant Sen's Slope (significant trend detected).

Canadian Ambient Air Quality Standard reporting

PM2.5 and ozone CAAQS metric values for designated sites across Ontario (2020)

Air zone area City/Town 24-hour PM2.5
(μg/m3)		 Annual PM2.5
(μg/m3)		 8-hour ozone
(ppb)
Sarnia Sarnia 19 7.2 72*(41)
Hamilton Hamilton Downtown 22 8.7 62(48)
Hamilton Hamilton Mountain 19 8.6 66*(51)
Sudbury Sudbury 14 5.2 60(45)
Sault Ste. Marie Sault Ste. Marie 13 4.9 60(46)
Northern Ontario Thunder Bay 14 5.5 50(46)
Southern Ontario Windsor Downtown 19 7.8 71*(42)
Southern Ontario Chatham 17 6.8 63*(42)
Southern Ontario London 18 6.8 64*(49)
Southern Ontario Brantford 18 7.3 63*(49)
Southern Ontario Kitchener 19 7.1 62(49)
Southern Ontario Guelph 20 7.1 61(51)
Southern Ontario St. Catharines 17 6.8 62(49)
Southern Ontario Burlington 18 6.9 65*(53)
Southern Ontario Oakville 18 6.9 65*(50)
Southern Ontario Milton 19 7.4 65*(52)
Southern Ontario Mississauga 18 7.0 61(47)
Southern Ontario Brampton 19 7.0 66*(52)
Southern Ontario Toronto West 18 7.2 63*(48)
Southern Ontario Toronto Downtown INS INS INS
Southern Ontario Toronto North 19 7.0 66*(51)
Southern Ontario Toronto East 19 7.0 61(45)
Southern Ontario Oshawa 17 6.2 62(48)
Southern Ontario Barrie 20 7.0 60(47)
Southern Ontario Peterborough 17 6.0 61(48)
Southern Ontario Kingston 14 5.5 63*(47)
Southern Ontario Ottawa Downtown 16 5.9 55(47)

Note:

  • Designated sites normally refer to communities with populations greater than 100,000.
  • The CAAQS for 24h PM2.5 is 27 μg/m3 based on the 98th percentile measurement annually, averaged over three consecutive years.
  • The CAAQS for annual PM2.5 is 8.8 μg/m3 based on the annual average of the daily 24-hour average concentrations averaged over three consecutive years.
  • The CAAQS for ozone is 62 ppb based on the consecutive three-year average of the annual 4th highest daily maximum eight-hour running average.
  • An asterisk denotes an exceedance of the CAAQS.
  • INS denotes insufficient data to report a valid CAAQS metric.
  • Value in parenthesis is the calculated 8h ozone CAAQS metric once the transboundary influence was removed.

NO2 and SO2 CAAQS metric values for designated sites across Ontario (2020)

Air zone area City/Town 1-hour NO2 (ppb) Annual NO2 (ppb) 1-hour SO2 (ppb) Annual SO2 (ppb)
Sarnia Sarnia 36 5.9 61 2.0
Hamilton Hamilton Downtown 43 9.9 87* 3.7
Hamilton Hamilton Mountain 41 6.9 57 2.5
Sudbury Sudbury 49 6.3 46 0.9
Sault Ste. Marie Sault Ste. Marie 32 3.7 37 0.6
Northern Ontario Thunder Bay 42 6.1 N/A N/A
Southern Ontario Windsor Downtown 44 9.0 15 0.3
Southern Ontario Chatham 31 5.1 N/A N/A
Southern Ontario London 31 4.5 N/A N/A
Southern Ontario Brantford 28 4.3 N/A N/A
Southern Ontario Kitchener 36 4.9 N/A N/A
Southern Ontario Guelph 34 4.9 N/A N/A
Southern Ontario St. Catharines 34 5.3 N/A N/A
Southern Ontario Burlington 43 8.2 N/A N/A
Southern Ontario Oakville 43 6.8 N/A N/A
Southern Ontario Milton 51 7.6 N/A N/A
Southern Ontario Mississauga 38 6.7 N/A N/A
Southern Ontario Brampton 45 6.8 N/A N/A
Southern Ontario Toronto West 51 12.1 7 0.2
Southern Ontario Toronto Downtown INS 12.3 N/A N/A
Southern Ontario Toronto North 45 8.9 5 0.1
Southern Ontario Toronto East 47 8.4 N/A N/A
Southern Ontario Oshawa 23 3.6 N/A N/A
Southern Ontario Barrie 40 5.6 N/A N/A
Southern Ontario Peterborough 34 4.0 N/A N/A
Southern Ontario Kingston 32 3.5 N/A N/A
Southern Ontario Ottawa Downtown 41 5.9 2 0.1

Note:

  • Designated sites normally refer to communities with populations greater than 100,000.
  • The CAAQS for 1h NO2 is 60 ppb is based on the 3-year average of the annual 98th percentile of the daily maximum 1-hour average NO2 concentrations.
  • The CAAQS for annual NO2 is 17.0 ppb based on the average over a single calendar year of all the 1h average NO2 concentrations.
  • The CAAQS for 1h SO2 is 70 ppb based on the 3-year average of the annual 99th percentile of the SO2 daily maximum 1-hour average concentrations.
  • The CAAQS for annual SO2 is 5.0 ppb based on the average over a single calendar year of all 1h average SO2 concentrations.
  • An asterisk denotes an exceedance of the CAAQS.
  • INS denotes insufficient data to report a valid CAAQS metric.
  • N/A denotes not applicable (parameter not monitored at location).

PM2.5 and ozone CAAQS metric trends for designated sites across Ontario (2011-2020)

Air zone area City/Town 10-year trend (%) based on
24-hour PM2.5		 10-year trend (%) based on
annual PM2.5		 10-year trend (%) based on
8-hour ozone
Sarnia Sarnia -34.5 -50.0 0.0*
Hamilton Hamilton Downtown -27.0 -14.5 -7.5
Hamilton Hamilton Mountain -13.6 -9.6* -7.7
Sudbury Sudbury 0.0* -15.0 -11.9
Sault Ste. Marie Sault Ste. Marie -24.1 -14.3* -10.9
Northern Ontario Thunder Bay -11.3 -8.0* -11.1
Southern Ontario Windsor Downtown -18.8 -19.1 -9.6
Southern Ontario Chatham -21.4 -19.4 -16.7
Southern Ontario London -12.9* -17.8 -11.9*
Southern Ontario Brantford -20.5 -11.2* -14.1
Southern Ontario Kitchener -14.3 -10.2* -8.2
Southern Ontario Guelph -7.1* -3.5* -13.0
Southern Ontario St. Catharines -21.4 -17.3 -10.7
Southern Ontario Burlington -20.5 -14.4* -3.4*
Southern Ontario Oakville -12.9 -10.8* -6.5
Southern Ontario Milton -10.7* -7.4* -4.3
Southern Ontario Mississauga -14.3* -8.5* -6.9
Southern Ontario Brampton -6.1* -6.2* -3.3*
Southern Ontario Toronto West -18.4 -22.0 -11.3
Southern Ontario Toronto Downtown INS INS INS
Southern Ontario Toronto North -27.7 -23.3 0.0*
Southern Ontario Toronto East -13.6 -13.0 -10.2
Southern Ontario Oshawa -16.9 -14.9* -9.9
Southern Ontario Barrie 0.0* 3.7* -9.7
Southern Ontario Peterborough -22.5 -11.7 -12.7
Southern Ontario Kingston -50.4 -39.8 -12.2
Southern Ontario Ottawa Downtown -21.4 -8.4* -5.2*

Notes:

  • Designated sites normally refer to communities with populations greater than 100,000.
  • *Non-Significant Sen’s Slope (significant trend not detected).
  • INS denotes insufficient data for a valid 10-year trend.

NO2 and SO2 CAAQS metric trends for designated sites across Ontario (2011-2020)

Air zone area City/Town 10-year trend (%) based on
1-hour NO2		 10-year trend (%) based on
annual NO2		 10-year trend (%) based on
1-hour SO2		 10-year trend (%) based on
annual SO2
Sarnia Sarnia 0.0* -22.9 -40.6 -50.4
Hamilton Hamilton Downtown -9.4 -14.1 15.0* -19.9
Hamilton Hamilton Mountain 0.0* -19.5 -36.0 -29.2
Sudbury Sudbury INS -12.6 -29.2* -60.0
Sault Ste. Marie Sault Ste. Marie -11.8 -25.5 -5.1* -11.8*
Northern Ontario Thunder Bay 0.0* -19.6 N/A N/A
Southern Ontario Windsor Downtown -19.0 -26.9 -77.6 -86.7
Southern Ontario Chatham -12.5 -17.3 N/A N/A
Southern Ontario London -20.0 -25.5 N/A N/A
Southern Ontario Brantford -23.7 -11.6 N/A N/A
Southern Ontario Kitchener -20.0 -22.5 N/A N/A
Southern Ontario Guelph -14.8 -24.5 N/A N/A
Southern Ontario St. Catharines -15.0 -34.5 N/A N/A
Southern Ontario Burlington -7.5 -22.5 N/A N/A
Southern Ontario Oakville -12.5 -20.1 N/A N/A
Southern Ontario Milton 0.0* -16.7 -37.0* -34.6
Southern Ontario Mississauga -15.7 -27.9 N/A N/A
Southern Ontario Brampton -11.5 -31.4 N/A N/A
Southern Ontario Toronto West -12.2 -26.6 -46.2 -52.2
Southern Ontario Toronto Downtown INS INS INS INS
Southern Ontario Toronto North -11.3 -35.6 N/A N/A
Southern Ontario Toronto East -6.8* -41.0 N/A N/A
Southern Ontario Oshawa -7.9* -36.3 N/A N/A
Southern Ontario Barrie -5.6* -27.4 N/A N/A
Southern Ontario Peterborough 0.0* -25.9 N/A N/A
Southern Ontario Kingston 0.0* -12.4 N/A N/A
Southern Ontario Ottawa Downtown 0.0* -20.9 -56.3 -25.0

Notes:

  • Designated sites normally refer to communities with populations greater than 100,000.
  • *Non-Significant Sen’s Slope (significant trend not detected).
  • INS denotes insufficient data for a valid 10-year trend.
  • N/A denotes not applicable (parameter not monitored at location).
  • Milton is based on 8 years of available data.

Management levels for Canadian Ambient Air Quality Standard pollutants

Ozone

Management level 8-hour
2020
Red > 62 ppb
Orange 57 to 62 ppb
Yellow 51 to 56 ppb
Green ≤ 50 ppb

Fine particulate matter (PM2.5)

Management Level 24-hour
2020		 Annual
2020
Red > 27 µg/m3 > 8 µg/m3
Orange 20 to 27 µg/m3 6.5 to 8.8 µg/m3
Yellow 11 to 19 µg/m3 4.1 to 6.4 µg/m3
Green ≤ 10 µg/m3 ≤ 4.0 µg/m3

Sulphur dioxide (SO2)

Management Level 1-hour
2020		 Annual
2020
Red > 70 ppb > 5.0 ppb
Orange 51 to 70 ppb 3.1 to 5.0 ppb
Yellow 31 to 50 ppb 2.1 to 3.0 ppb
Green ≤ 30 ppb ≤ 2.0 ppb

Nitrogen dioxide (NO2)

Management Level 1-hour
2020		 Annual
2020
Red > 60 ppb > 17.0 ppb
Orange 32 to 60 ppb 7.1 to 17.0 ppb
Yellow 21 to 30 ppb 2.1 to 7.0 ppb
Green ≤ 20 ppb ≤ 2.0 ppb

AQHI and Air Quality Alert Program Reporting

2020 Air Quality Health Index summary

Station ID City/Town No. of valid hours Low risk AQHI=1 Low risk AQHI=2 Low risk AQHI=3 Moderate risk AQHI=4 Moderate risk AQHI=5 Moderate risk AQHI=6 High risk AQHI=7 High risk AQHI=8 High risk AQHI=9 High risk AQHI=10 Very high risk AQHI=+ No. of days at least 1 hour > 6
12008 Windsor Downtown 8714 2.90 51.54 38.54 6.61 0.40 0 0.01 0 0 0 0 1
12016 Windsor West 8370 4.17 53.73 36.50 5.20 0.38 0 0.02 0 0 0 0 1
13001 Chatham 8699 9.92 61.13 24.96 3.81 0.18 0 0 0 0 0 0 0
14111 Sarnia 8729 11.51 61.90 21.46 4.40 0.72 0 0.01 0 0 0 0 1
15020 Grand Bend 8621 17.09 66.37 14.07 2.18 0.15 0 0.14 0 0 0 0 5
15026 London 8619 14.29 62.15 21.26 2.26 0.03 0 0 0 0 0 0 0
16015 Port Stanley 8559 14.24 61.95 20.76 2.80 0.25 0 0 0 0 0 0 0
18007 Tiverton 8339 14.64 67.86 15.73 1.73 0.04 0 0 0 0 0 0 0
21005 Brantford 8657 14.01 60.88 22.43 2.62 0.06 0 0 0 0 0 0 0
26060 Kitchener 8679 12.70 61.80 23.42 2.03 0.05 0 0 0 0 0 0 0
27067 St. Catharines 8685 7.29 58.63 30.74 3.29 0.05 0 0 0 0 0 0 0
28028 Guelph 8696 14.20 61.28 21.81 2.64 0.06 0 0 0 0 0 0 0
29000 Hamilton Downtown 8737 3.55 46.18 40.47 8.47 0.98 0.34 0 0 0 0 0 0
29118 Hamilton West 8608 5.96 49.72 36.80 6.66 0.76 0.10 0 0 0 0 0 0
29214 Hamilton Mountain 8740 5.90 52.71 33.92 6.70 0.66 0.09 0 0 0 0 0 0
31129 Toronto Downtown 8597 3.43 41.29 43.64 9.56 1.88 0.19 0 0 0 0 0 0
33003 Toronto East 8722 7.44 55.00 31.09 5.82 0.60 0.05 0 0 0 0 0 0
34021 Toronto North 8684 8.65 50.26 34.55 5.78 0.63 0.02 0.10 0 0 0 0 4
35125 Toronto West 8612 3.89 45.05 42.86 7.37 0.69 0.13 0.01 0 0 0 0 1
44008 Burlington 8752 5.12 51.51 36.79 5.92 0.64 0 0.02 0 0 0 0 1
44017 Oakville 8671 7.61 57.84 29.96 4.17 0.40 0 0.01 0 0 0 0 1
44029 Milton 8451 7.03 55.51 32.27 4.72 0.47 0 0 0 0 0 0 0
45027 Oshawa 8477 22.51 61.27 13.85 2.01 0.31 0.01 0.05 0 0 0 0 1
46090 Brampton 8723 8.77 53.90 31.51 4.95 0.83 0 0.03 0 0 0 0 2
46108 Mississauga 8728 11.70 60.55 24.53 3.00 0.22 0 0 0 0 0 0 0
47045 Barrie 8347 17.73 55.16 23.67 3.28 0.16 0 0 0 0 0 0 0
48006 Newmarket 8747 15.08 59.45 22.57 2.62 0.25 0 0.03 0 0 0 0 3
49005 Parry Sound 8674 21.96 60.18 16.66 1.19 0.01 0 0 0 0 0 0 0
49010 Dorset 8623 26.58 58.48 14.45 0.48 0.01 0 0 0 0 0 0 0
51001 Ottawa Downtown 8720 19.71 54.27 23.20 2.58 0.24 0 0 0 0 0 0 0
51010 Petawawa 8560 28.79 57.21 13.66 0.35 0 0 0 0 0 0 0 0
52023 Kingston 8586 13.72 63.92 20.24 2.12 0 0 0 0 0 0 0 0
54012 Belleville 8577 13.20 63.04 20.79 2.89 0.07 0 0.01 0 0 0 0 1
56051 Cornwall 8727 18.55 61.80 17.54 1.96 0.15 0 0 0 0 0 0 0
59006 Peterborough 8376 20.49 58.39 18.82 2.16 0.12 0 0.02 0 0 0 0 1
63203 Thunder Bay 8701 22.80 60.14 15.44 1.45 0.17 0 0 0 0 0 0 0
71078 Sault Ste. Marie 8506 21.53 61.11 15.87 1.40 0.09 0 0 0 0 0 0 0
75010 North Bay 8743 24.85 59.16 14.72 1.25 0.02 0 0 0 0 0 0 0
77233 Sudbury 8734 21.42 55.61 19.91 2.86 0.19 0 0 0 0 0 0 0

2020 air quality alert summary

Air quality forecast region Special air quality statement Smog and air health advisory
Algonquin 0 0
Atikokan - Upsala - Quetico 0 0
Attawapiskat 0 0
Bancroft - Bon Echo Park 0 0
Barrie - Orillia - Midland 0 0
Belleville - Quinte - Northumberland 0 0
Big Trout Lake - Sachigo Lake 0 0
Brockville - Leeds and Grenville 0 0
Burk's Falls - Bayfield Inlet 0 0
Chapleau - Gogama 0 0
City of Hamilton 0 0
City of Ottawa 0 0
City of Thunder Bay 0 0
City of Toronto 2 0
Cornwall - Morrisburg 0 0
Dryden - Ignace 0 0
Dufferin - Innisfil 0 0
Dunnville - Caledonia - Haldimand 0 0
Elgin 1 0
Elliot Lake - Ranger Lake 0 0
Fort Frances - Rainy Lake 0 0
Fort Hope - Webequie 1 0
Fort Severn 0 0
Geraldton - Manitouwadge - Hornepayne 1 0
Greater Sudbury and Vicinity 0 0
Grey - Bruce 0 0
Haliburton 0 0
Halton - Peel 2 0
Huron - Perth 2 0
Kapuskasing - Hearst 0 0
Kenora - Nestor Falls 0 0
Kingston - Prince Edward 0 0
Kirkland Lake - New Liskeard - Temagami 0 0
Lake Nipigon - Wabakimi 0 0
London - Middlesex 1 0
Manitoulin - Northshore - Killarney 0 0
Moosonee - Fort Albany 0 0
Niagara 0 0
Nipigon - Marathon - Superior North 0 0
North Bay - West Nipissing 0 0
Oxford - Brant 0 0
Parry Sound - Muskoka 0 0
Peawanuck 0 0
Peterborough - Kawartha Lakes 0 0
Pickle Lake - Wunnummin Lake 1 0
Prescott and Russell 0 0
Red Lake - Ear Falls 1 0
Renfrew - Pembroke - Barry's Bay 0 0
Sandy Lake - Pikangikum 1 0
Sarnia - Lambton 4 0
Sault Ste. Marie - Superior East 0 0
Simcoe - Delhi - Norfolk 0 0
Sioux Lookout - Savant Lake 0 0
Smiths Falls - Lanark - Sharbot Lake 0 0
Stirling - Tweed - South Frontenac 0 0
Superior West 0 0
Timmins - Cochrane 0 0
Waterloo - Wellington 0 0
Wawa - White River - Pukaskwa 0 0
Windsor - Essex - Chatham - Kent 4 0
York - Durham 2 0
Ontario 6 0

COVID‑19 pandemic period

Traffic volumes and air pollution concentrations in baseline years and changes in 2020 at the Highway 401 roadside station

Means in baseline years
Parameter Pre-COVID period Stay-at-home period Re-opening period
Car volume (counts/hour) 7340 7569 7639
Truck volume (counts/hour) 1146 1353 1302
BC (µg/m3) 1.2 1.2 1.6
NO2 (ppb) 22.6 19.2 17.2
PM2.5 (µg/m3) 10.6 8.0 8.8
O3 (ppb) 18.2 24.0 17.4
Changed means in 2020 relative to the baseline years
Parameter Pre-COVID period Stay-at-home period Re-opening period
Car volume (counts/hour) 134 -2349 -924
Truck volume (counts/hour) 13 -281 11
BC (µg/m3) 0.05 -0.27 -0.30
NO2 (ppb) -2.2 -4.2 -2.3
PM2.5 (µg/m3) -1.6 -1.2 0.4
O3 (ppb) -0.5 -0.5 1.1
Changes attributable to the pandemic (%)
Parameter Stay-at-home period Re-opening period
Car volume (counts/hour) -33% -14%
Truck volume (counts/hour) -22% 0%
BC (µg/m3) -27% -23%
NO2 (ppb) -10% 0%
PM2.5 (µg/m3) 6% 23%
O3 (ppb) 0% 9%

Notes:

  • Baseline years: 2017-2019.
  • Pre-COVID period: January 1 - March 18; Stay-at-home period: March 19 - May 18; Re-opening period: May 19 - December 31.

Baseline concentrations of black carbon and changes in 2020

Means in baseline years (µg/m3)
ID City/Town Pre-COVID period Stay-at-home period Re-opening period
12008 Windsor Downtown 0.4 0.4 0.6
29000 Hamilton Downtown 0.5 0.7 0.8
33003 Toronto East 0.4 0.4 0.6
34021 Toronto North 0.4 0.4 0.6
35033 Etobicoke South 0.7 0.8 0.9
83126 Highway 401 1.2 1.2 1.6
Changed means in 2020 relative to the baseline years (µg/m3)
ID City/Town Pre-COVID period Stay-at-home period Re-opening period
12008 Windsor Downtown 0 -0.14 -0.16
29000 Hamilton Downtown 0.02 -0.18 -0.15
33003 Toronto East 0.02 -0.07 -0.09
34021 Toronto North 0.06 -0.08 -0.05
35033 Etobicoke South 0.07 -0.08 0.03
83126 Highway 401 0.05 -0.27 -0.30
Changes attributable to the pandemic (%)
ID City/Town Stay-at-home period Re-opening period
12008 Windsor Downtown -34% -25%
29000 Hamilton Downtown -28% -22%
33003 Toronto East -24% -19%
34021 Toronto North -31% -17%
35033 Etobicoke South -20% -4%
83126 Highway 401 -27% -23%

Notes:

  • Baseline years: 2017-2019.
  • Pre-COVID period: January 1 - March 18; Stay-at-home period: March 19 - May 18; Re-opening period: May 19 - December 31.

Baseline concentrations of nitrogen dioxide and changes in 2020

Means in baseline years (ppb)
ID City/Town Pre-COVID period Stay-at-home period Re-opening period
12008 Windsor Downtown 14.2 10.2 10.1
29000 Hamilton Downtown 13.6 13.0 11.2
29118 Hamilton West 12.4 11.7 10.2
33003 Toronto East 13.8 9.9 10.0
34021 Toronto North 13.6 9.8 9.7
35033 Etobicoke South 17.4 15.4 14.0
35125 Toronto West 18.2 14.0 13.6
63203 Thunder Bay 11.0 7.6 5.4
75010 North Bay 8.1 4.8 3.8
83126 Highway 401 22.6 19.2 17.2
Changed means in 2020 relative to the baseline years (ppb)
ID City/Town Pre-COVID period Stay-at-home period Re-opening period
12008 Windsor Downtown 3.1 -2.6 -1.9
29000 Hamilton Downtown -1.7 -3.0 -2.3
29118 Hamilton West -1.4 -2.1 -1.4
33003 Toronto East -2.7 -3.1 -2.2
34021 Toronto North -2.0 -2.1 -1.4
35033 Etobicoke South -1.3 -3.7 -2.9
35125 Toronto West -1.8 -3.5 -2.8
63203 Thunder Bay -1.1 -1.6 -0.5
75010 North Bay -1.1 -1.4 -0.4
83126 Highway 401 -2.2 -4.2 -2.3
Changes attributable to the pandemic (%)
ID City/Town Stay-at-home period Re-opening period
12008 Windsor Downtown -1% 6%
29000 Hamilton Downtown -10% -5%
29118 Hamilton West -6% 0%
33003 Toronto East -5% 5%
34021 Toronto North -1% 6%
35033 Etobicoke South -16% -12%
35125 Toronto West -12% -7%
63203 Thunder Bay -7% 10%
75010 North Bay -5% 19%
83126 Highway 401 -10% 0%

Notes:

  • Baseline years: 2017-2019.
  • Pre-COVID period: January 1 - March 18; Stay-at-home period: March 19 - May 18; Re-opening period: May 19 - December 31.

Baseline concentrations of fine particulate matter and changes in 2020

Means in baseline years (µg/m3)
ID City/Town Pre-COVID period Stay-at-home period Re-opening period
12008 Windsor Downtown 9.0 6.9 8.0
29000 Hamilton Downtown 8.8 9.0 8.8
29118 Hamilton West 8.2 7.7 7.8
33003 Toronto East 8.1 6.4 7.1
34021 Toronto North 8.2 6.5 7.2
35033 Etobicoke South 8.8 7.6 7.9
35125 Toronto West 8.1 6.3 7.5
63203 Thunder Bay 5.8 4.6 5.5
75010 North Bay 4.9 4.4 5.0
83126 Highway 401 10.6 8.0 8.8
Changed means in 2020 relative to the baseline years (µg/m3)
ID City/Town Pre-COVID period Stay-at-home period Re-opening period
12008 Windsor Downtown -1.4 -1.0 -0.8
129000 Hamilton Downtown -0.9 -1.2 -0.6
129118 Hamilton West -1.0 -0.8 0.5
133003 Toronto East -0.9 -0.4 -0.4
134021 Toronto North -1.2 -1.0 -0.7
135033 Etobicoke South -1.3 -1.3 -0.3
135125 Toronto West -1.2 -0.5 -0.4
163203 Thunder Bay -0.4 0.4 0.2
175010 North Bay -0.3 -0.5 -0.2
183126 Highway 401 -1.6 -1.2 0.4
Changes attributable to the pandemic (%)
ID City/Town Stay-at-home period Re-opening period
12008 Windsor Downtown 6% 7%
29000 Hamilton Downtown -2% 4%
329118 Hamilton West 3% 19%
33003 Toronto East 8% 8%
34021 Toronto North 2% 7%
35033 Etobicoke South 0% 12%
335125 Toronto West 11% 11%
363203 Thunder Bay 17% 10%
375010 North Bay -5% 1%
83126 Highway 401 6% 23%

Notes:

  • Baseline years: 2017-2019.
  • Pre-COVID period: January 1 - March 18; Stay-at-home period: March 19 - May 18; Re-opening period: May 19 - December 31.

Baseline concentrations of ozone and changes in 2020

Means in baseline years (ppb)
ID City/Town Pre-COVID period Stay-at-home period Re-opening period
12008 Windsor Downtown 23.6 32.2 26.6
29000 Hamilton Downtown 25.1 29.9 23.9
29118 Hamilton West 25.2 30.1 23.0
33003 Toronto East 24.6 30.5 23.2
34021 Toronto North 24.1 30.8 23.0
35033 Etobicoke South 21.8 26.9 21.3
35125 Toronto West 21.1 27.7 20.8
63203 Thunder Bay 26.9 31.8 20.6
75010 North Bay 28.1 32.7 23.9
83126 Highway 401 18.2 24.0 17.4
Changed means in 2020 relative to the baseline years (ppb)
ID City/Town Pre-COVID period Stay-at-home period Re-opening period
12008 Windsor Downtown -0.4 -1.6 1.2
129000 Hamilton Downtown 0.1 -0.8 1.9
129118 Hamilton West -1.4 -1.0 1.6
133003 Toronto East 0.2 0.3 2.0
134021 Toronto North 0.4 -0.2 2.2
135033 Etobicoke South 0.1 0.3 0.8
135125 Toronto West 1.2 0.4 1.6
163203 Thunder Bay -1.7 -2.8 0.0
175010 North Bay 1.3 0.3 -0.7
183126 Highway 401 -0.5 -0.5 1.1
Changes attributable to the pandemic (%)
ID City/Town Stay-at-home period Re-opening period
12008 Windsor Downtown -4% 6%
29000 Hamilton Downtown -3% 8%
329118 Hamilton West 1% 13%
33003 Toronto East 1% 8%
34021 Toronto North -2% 8%
35033 Etobicoke South 1% 3%
335125 Toronto West -3% 2%
363203 Thunder Bay -4% 8%
375010 North Bay -3% -8%
83126 Highway 401 0% 9%

Notes:

  • Baseline years: 2017-2019.
  • Pre-COVID period: January 1 - March 18; Stay-at-home period: March 19 - May 18; Re-opening period: May 19 - December 31.