Pollutant concentrations for December 24, 2025, 5:00 am EST

Choose date options.

Pollutant concentrations for December 24, 2025, 5:00 am EST
Station O3 (ppb) PM2.5 (µg/m3) NO2 (ppb) SO2 (ppb) CO (ppm)
Barrie 30Barrie graph for O3 1Barrie graph for PM2.5 1.2Barrie graph for NO2    
Belleville 28Belleville graph for O3 3Belleville graph for PM2.5 2.5Belleville graph for NO2    
Brampton 30Brampton graph for O3 4Brampton graph for PM2.5 2Brampton graph for NO2    
Brantford 30Brantford graph for O3 5Brantford graph for PM2.5 0.9Brantford graph for NO2    
Burlington 30Burlington graph for O3 5Burlington graph for PM2.5 3.7Burlington graph for NO2    
Chatham 19Chatham graph for O3 14Chatham graph for PM2.5 6.2Chatham graph for NO2    
Cornwall 10Cornwall graph for O3 14Cornwall graph for PM2.5 12.4Cornwall graph for NO2    
Dorset 30Dorset graph for O3 2Dorset graph for PM2.5      
Grand Bend 34Grand Bend graph for O3 5Grand Bend graph for PM2.5 1Grand Bend graph for NO2    
Guelph 30Guelph graph for O3 5Guelph graph for PM2.5 2.3Guelph graph for NO2    
Hamilton Downtown 29Hamilton Downtown graph for O3 5Hamilton Downtown graph for PM2.5 3.6Hamilton Downtown graph for NO2 0Hamilton Downtown graph for SO2 0.15Hamilton Downtown graph for CO
Hamilton Mountain 28Hamilton Mountain graph for O3 5Hamilton Mountain graph for PM2.5 3.6Hamilton Mountain graph for NO2 0.3Hamilton Mountain graph for SO2  
Hamilton West 28Hamilton West graph for O3 5Hamilton West graph for PM2.5 3.7Hamilton West graph for NO2    
Kingston 25Kingston graph for O3 3Kingston graph for PM2.5 2.7Kingston graph for NO2    
Kitchener 30Kitchener graph for O3 5Kitchener graph for PM2.5 2.5Kitchener graph for NO2    
London 30London graph for O3 6London graph for PM2.5 4London graph for NO2    
Milton 27Milton graph for O3 5Milton graph for PM2.5 3Milton graph for NO2 0.2Milton graph for SO2  
Mississauga 29Mississauga graph for O3 4Mississauga graph for PM2.5 2.9Mississauga graph for NO2    
Newmarket 31Newmarket graph for O3 3Newmarket graph for PM2.5 1.3Newmarket graph for NO2    
North Bay 32North Bay graph for O3 2North Bay graph for PM2.5 0.8North Bay graph for NO2    
Oakville 30Oakville graph for O3 4Oakville graph for PM2.5 1.4Oakville graph for NO2    
Oshawa 30Oshawa graph for O3 3Oshawa graph for PM2.5 0.5Oshawa graph for NO2    
Ottawa Downtown 16Ottawa Downtown graph for O3 9Ottawa Downtown graph for PM2.5 7.2Ottawa Downtown graph for NO2    
Parry Sound 31Parry Sound graph for O3 2Parry Sound graph for PM2.5 0.9Parry Sound graph for NO2    
Peterborough 28Peterborough graph for O3 3Peterborough graph for PM2.5 0.6Peterborough graph for NO2    
Port Stanley 27Port Stanley graph for O3 7Port Stanley graph for PM2.5 2.1Port Stanley graph for NO2    
Sarnia 22Sarnia graph for O3 12Sarnia graph for PM2.5 2.9Sarnia graph for NO2 0.2Sarnia graph for SO2  
Sault Ste. Marie 31Sault Ste. Marie graph for O3 2Sault Ste. Marie graph for PM2.5 1.2Sault Ste. Marie graph for NO2 0Sault Ste. Marie graph for SO2  
St. Catharines 31St. Catharines graph for O3 4St. Catharines graph for PM2.5 1.7St. Catharines graph for NO2    
Sudbury 29Sudbury graph for O3 2Sudbury graph for PM2.5 1.7Sudbury graph for NO2 0.1Sudbury graph for SO2  
Thunder Bay 19Thunder Bay graph for O3 4Thunder Bay graph for PM2.5 9.6Thunder Bay graph for NO2    
Tiverton 28Tiverton graph for O3 4Tiverton graph for PM2.5      
Toronto Downtown 24Toronto Downtown graph for O3 5Toronto Downtown graph for PM2.5 8Toronto Downtown graph for NO2    
Toronto East 27Toronto East graph for O3 4Toronto East graph for PM2.5 2.7Toronto East graph for NO2    
Toronto North 25Toronto North graph for O3 5Toronto North graph for PM2.5 4.1Toronto North graph for NO2 0.4Toronto North graph for SO2  
Toronto West 21Toronto West graph for O3 5Toronto West graph for PM2.5 5.4Toronto West graph for NO2 0.1Toronto West graph for SO2 0.15Toronto West graph for CO
Windsor Downtown 6Windsor Downtown graph for O3 24Windsor Downtown graph for PM2.5 21.6Windsor Downtown graph for NO2 0Windsor Downtown graph for SO2 N/AWindsor Downtown graph for CO
Windsor West 2Windsor West graph for O3 27Windsor West graph for PM2.5 24.2Windsor West graph for NO2 N/AWindsor 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.

Disclaimer