Pollutant concentrations for
September 18, 2025, 1:00 am EDT

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Pollutant concentrations for
September 18, 2025, 1:00 am EDT September 18, 2025, 1:00 am EDT

Station	O3 (ppb)	PM2.5 (µg/m3)	NO2 (ppb)	SO2 (ppb)	CO (ppm)
Barrie	N/A	N/A	N/A
Belleville	N/A	N/A	N/A
Brampton	N/A	N/A	N/A
Brantford	14	10	2.6
Burlington	1	8	33.1
Chatham	36	8	4
Cornwall	N/A	N/A	N/A
Dorset	N/A	N/A
Grand Bend	N/A	N/A	N/A
Guelph	17	9	6.2
Hamilton Downtown	N/A	N/A	N/A	N/A	N/A
Hamilton Mountain	10	9	11.4	0
Hamilton West	1	8	16.2
Kingston	N/A	N/A	N/A
Kitchener	24	10	7.1
London	13	10	6.8
Milton	1	13	22.9	0.3
Mississauga	N/A	N/A	N/A
Newmarket	N/A	N/A	N/A
North Bay	N/A	N/A	N/A
Oakville	23	12	9.4
Oshawa	N/A	N/A	N/A
Ottawa Downtown	N/A	N/A	N/A
Parry Sound	N/A	N/A	N/A
Peterborough	N/A	N/A	N/A
Port Stanley	33	8	1.9
Sarnia	4	14	17.3	0
Sault Ste. Marie	N/A	N/A	N/A	N/A
St. Catharines	12	12	7.6
Sudbury	N/A	N/A	N/A	N/A
Thunder Bay	N/A	N/A	N/A
Tiverton	25	4
Toronto Downtown	3	28	42.2
Toronto East	3	14	28.2
Toronto North	4	12	16.2	0.2
Toronto West	2	14	28	0	0.52
Windsor Downtown	10	31	36.3	0	0.34
Windsor West	12	19	17.4	0

Order by station location (east to west)

Note: 
Ontario 1-hour AAQC for O₃ = 80 ppb
Ontario 1-hour AAQC for NO₂ = 200 ppb
Ontario 1-hour AAQC for SO₂ = 40 ppb
Ontario 1-hour AAQC for CO = 30 ppm

Note: The pollutant concentrations on this web page are based on automatically polled data and have not undergone final verification.

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