Notice

The Toronto West AQHI station will experience a temporary interruption in public data reporting from Friday, April 10 to Sunday, April 12 due to scheduled maintenance activities. Air quality information from other Toronto monitoring stations will remain available.

Pollutant concentrations for April 11, 2026, 1:00 am EDT

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Pollutant concentrations for April 11, 2026, 1:00 am EDT
Station O3 (ppb) PM2.5 (µg/m3) NO2 (ppb) SO2 (ppb) CO (ppm)
Barrie 24Barrie graph for O3 3Barrie graph for PM2.5 5Barrie graph for NO2    
Belleville 22Belleville graph for O3 3Belleville graph for PM2.5 4.5Belleville graph for NO2    
Brampton 27Brampton graph for O3 3Brampton graph for PM2.5 6.2Brampton graph for NO2    
Brantford 33Brantford graph for O3 6Brantford graph for PM2.5 1.8Brantford graph for NO2    
Burlington 26Burlington graph for O3 4Burlington graph for PM2.5 7.2Burlington graph for NO2    
Chatham 30Chatham graph for O3 3Chatham graph for PM2.5 2Chatham graph for NO2    
Cornwall 25Cornwall graph for O3 3Cornwall graph for PM2.5 3Cornwall graph for NO2    
Dorset 29Dorset graph for O3 2Dorset graph for PM2.5      
Grand Bend 30Grand Bend graph for O3 3Grand Bend graph for PM2.5 0.8Grand Bend graph for NO2    
Guelph 31Guelph graph for O3 3Guelph graph for PM2.5 1.4Guelph graph for NO2    
Hamilton Downtown 23Hamilton Downtown graph for O3 5Hamilton Downtown graph for PM2.5 6.9Hamilton Downtown graph for NO2 0.7Hamilton Downtown graph for SO2 0.19Hamilton Downtown graph for CO
Hamilton Mountain 24Hamilton Mountain graph for O3 4Hamilton Mountain graph for PM2.5 5.5Hamilton Mountain graph for NO2 0.1Hamilton Mountain graph for SO2  
Hamilton West 22Hamilton West graph for O3 4Hamilton West graph for PM2.5 7.3Hamilton West graph for NO2    
Kingston 22Kingston graph for O3 4Kingston graph for PM2.5 2Kingston graph for NO2    
Kitchener 31Kitchener graph for O3 3Kitchener graph for PM2.5 2.6Kitchener graph for NO2    
London 29London graph for O3 3London graph for PM2.5 4.8London graph for NO2    
Milton 29Milton graph for O3 3Milton graph for PM2.5 4.5Milton graph for NO2 0.2Milton graph for SO2  
Mississauga 26Mississauga graph for O3 3Mississauga graph for PM2.5 5.1Mississauga graph for NO2    
Newmarket 28Newmarket graph for O3 3Newmarket graph for PM2.5 2.7Newmarket graph for NO2    
North Bay 34North Bay graph for O3 4North Bay graph for PM2.5 1.3North Bay graph for NO2    
Oakville 30Oakville graph for O3 3Oakville graph for PM2.5 4.2Oakville graph for NO2    
Oshawa 31Oshawa graph for O3 3Oshawa graph for PM2.5 0.7Oshawa graph for NO2    
Ottawa Downtown 24Ottawa Downtown graph for O3 4Ottawa Downtown graph for PM2.5 5.3Ottawa Downtown graph for NO2    
Parry Sound 33Parry Sound graph for O3 3Parry Sound graph for PM2.5 1.2Parry Sound graph for NO2    
Peterborough 30Peterborough graph for O3 3Peterborough graph for PM2.5 0.6Peterborough graph for NO2    
Port Stanley 27Port Stanley graph for O3 3Port Stanley graph for PM2.5 2.5Port Stanley graph for NO2    
Sarnia 37Sarnia graph for O3 2Sarnia graph for PM2.5 2.2Sarnia graph for NO2 0Sarnia graph for SO2  
Sault Ste. Marie 39Sault Ste. Marie graph for O3 4Sault Ste. Marie graph for PM2.5 3.1Sault Ste. Marie graph for NO2 0Sault Ste. Marie graph for SO2  
St. Catharines 34St. Catharines graph for O3 3St. Catharines graph for PM2.5 3.3St. Catharines graph for NO2    
Sudbury 39Sudbury graph for O3 3Sudbury graph for PM2.5 3.6Sudbury graph for NO2 0.1Sudbury graph for SO2  
Thunder Bay 35Thunder Bay graph for O3 6Thunder Bay graph for PM2.5 4.3Thunder Bay graph for NO2    
Tiverton 44Tiverton graph for O3 3Tiverton graph for PM2.5      
Toronto Downtown 23Toronto Downtown graph for O3 7Toronto Downtown graph for PM2.5 15Toronto Downtown graph for NO2    
Toronto East 22Toronto East graph for O3 3Toronto East graph for PM2.5 10.7Toronto East graph for NO2    
Toronto North 13Toronto North graph for O3 5Toronto North graph for PM2.5 17.8Toronto North graph for NO2 0Toronto North graph for SO2  
Toronto West 13Toronto West graph for O3 3Toronto West graph for PM2.5 21.8Toronto West graph for NO2 0Toronto West graph for SO2 0.28Toronto West graph for CO
Windsor Downtown 20Windsor Downtown graph for O3 10Windsor Downtown graph for PM2.5 13.3Windsor Downtown graph for NO2 0Windsor Downtown graph for SO2 0.2Windsor Downtown graph for CO
Windsor West 23Windsor West graph for O3 8Windsor West graph for PM2.5 7.7Windsor West graph for NO2 0Windsor West graph for SO2  

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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