Pollutant concentrations for May 23, 2026, 12:00 pm EDT

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Pollutant concentrations for May 23, 2026, 12:00 pm EDT
Station O3 (ppb) PM2.5 (µg/m3) NO2 (ppb) SO2 (ppb) CO (ppm)
Barrie 32Barrie graph for O3 4Barrie graph for PM2.5 1.9Barrie graph for NO2    
Belleville 39Belleville graph for O3 3Belleville graph for PM2.5 1.6Belleville graph for NO2    
Brampton 40Brampton graph for O3 3Brampton graph for PM2.5 4.5Brampton graph for NO2    
Brantford 36Brantford graph for O3 3Brantford graph for PM2.5 1.3Brantford graph for NO2    
Burlington 44Burlington graph for O3 4Burlington graph for PM2.5 1.6Burlington graph for NO2    
Chatham 36Chatham graph for O3 1Chatham graph for PM2.5 1.5Chatham graph for NO2    
Cornwall 39Cornwall graph for O3 4Cornwall graph for PM2.5 1.3Cornwall graph for NO2    
Dorset 42Dorset graph for O3 3Dorset graph for PM2.5      
Grand Bend 32Grand Bend graph for O3 3Grand Bend graph for PM2.5 3Grand Bend graph for NO2    
Guelph 39Guelph graph for O3 3Guelph graph for PM2.5 2.4Guelph graph for NO2    
Hamilton Downtown 29Hamilton Downtown graph for O3 8Hamilton Downtown graph for PM2.5 12.2Hamilton Downtown graph for NO2 0.9Hamilton Downtown graph for SO2 0.28Hamilton Downtown graph for CO
Hamilton Mountain 35Hamilton Mountain graph for O3 5Hamilton Mountain graph for PM2.5 6Hamilton Mountain graph for NO2 1.2Hamilton Mountain graph for SO2  
Hamilton West 31Hamilton West graph for O3 6Hamilton West graph for PM2.5 12.2Hamilton West graph for NO2    
Kingston 29Kingston graph for O3 3Kingston graph for PM2.5 2Kingston graph for NO2    
Kitchener 38Kitchener graph for O3 3Kitchener graph for PM2.5 2.4Kitchener graph for NO2    
London 36London graph for O3 2London graph for PM2.5 0.9London graph for NO2    
Milton 44Milton graph for O3 3Milton graph for PM2.5 0.2Milton graph for NO2 0.2Milton graph for SO2  
Mississauga 39Mississauga graph for O3 4Mississauga graph for PM2.5 1.5Mississauga graph for NO2    
Newmarket 40Newmarket graph for O3 4Newmarket graph for PM2.5 2.3Newmarket graph for NO2    
North Bay 39North Bay graph for O3 5North Bay graph for PM2.5 0.6North Bay graph for NO2    
Oakville 37Oakville graph for O3 5Oakville graph for PM2.5 4.4Oakville graph for NO2    
Oshawa 40Oshawa graph for O3 4Oshawa graph for PM2.5 2.2Oshawa graph for NO2    
Ottawa Downtown 39Ottawa Downtown graph for O3 4Ottawa Downtown graph for PM2.5 2.4Ottawa Downtown graph for NO2    
Parry Sound 44Parry Sound graph for O3 7Parry Sound graph for PM2.5 1.9Parry Sound graph for NO2    
Peterborough 35Peterborough graph for O3 4Peterborough graph for PM2.5 2.4Peterborough graph for NO2    
Port Stanley 38Port Stanley graph for O3 1Port Stanley graph for PM2.5 1.6Port Stanley graph for NO2    
Sarnia 36Sarnia graph for O3 1Sarnia graph for PM2.5 2.4Sarnia graph for NO2 0Sarnia graph for SO2  
Sault Ste. Marie 43Sault Ste. Marie graph for O3 3Sault Ste. Marie graph for PM2.5 1.4Sault Ste. Marie graph for NO2 0.1Sault Ste. Marie graph for SO2  
St. Catharines 38St. Catharines graph for O3 3St. Catharines graph for PM2.5 2.6St. Catharines graph for NO2    
Sudbury 39Sudbury graph for O3 4Sudbury graph for PM2.5 2Sudbury graph for NO2 0Sudbury graph for SO2  
Thunder Bay 36Thunder Bay graph for O3 3Thunder Bay graph for PM2.5 1.6Thunder Bay graph for NO2    
Tiverton 38Tiverton graph for O3 4Tiverton graph for PM2.5      
Toronto Downtown 30Toronto Downtown graph for O3 2Toronto Downtown graph for PM2.5 7.5Toronto Downtown graph for NO2    
Toronto East 40Toronto East graph for O3 4Toronto East graph for PM2.5 1.6Toronto East graph for NO2    
Toronto North 36Toronto North graph for O3 4Toronto North graph for PM2.5 2.9Toronto North graph for NO2 0Toronto North graph for SO2  
Toronto West 41Toronto West graph for O3 3Toronto West graph for PM2.5 2.8Toronto West graph for NO2 0Toronto West graph for SO2 0.13Toronto West graph for CO
Windsor Downtown 34Windsor Downtown graph for O3 1Windsor Downtown graph for PM2.5 2.2Windsor Downtown graph for NO2 0Windsor Downtown graph for SO2 0.16Windsor Downtown graph for CO
Windsor West 33Windsor West graph for O3 1Windsor West graph for PM2.5 1.5Windsor 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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