Pollutant concentrations for December 24, 2025, 3:00 am EST

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Pollutant concentrations for December 24, 2025, 3:00 am EST
Station O3 (ppb) PM2.5 (µg/m3) NO2 (ppb) SO2 (ppb) CO (ppm)
Barrie 29Barrie graph for O3 4Barrie graph for PM2.5 1.5Barrie graph for NO2    
Belleville 31Belleville graph for O3 4Belleville graph for PM2.5 1.6Belleville graph for NO2    
Brampton 32Brampton graph for O3 5Brampton graph for PM2.5 1.5Brampton graph for NO2    
Brantford 29Brantford graph for O3 5Brantford graph for PM2.5 0.8Brantford graph for NO2    
Burlington 32Burlington graph for O3 5Burlington graph for PM2.5 2.9Burlington graph for NO2    
Chatham 21Chatham graph for O3 12Chatham graph for PM2.5 7.8Chatham graph for NO2    
Cornwall 11Cornwall graph for O3 13Cornwall graph for PM2.5 12.8Cornwall graph for NO2    
Dorset 29Dorset graph for O3 1Dorset graph for PM2.5      
Grand Bend 34Grand Bend graph for O3 4Grand Bend graph for PM2.5 1.1Grand Bend graph for NO2    
Guelph 32Guelph graph for O3 6Guelph graph for PM2.5 1.7Guelph graph for NO2    
Hamilton Downtown 29Hamilton Downtown graph for O3 5Hamilton Downtown graph for PM2.5 4.4Hamilton Downtown graph for NO2 0.1Hamilton Downtown graph for SO2 0.15Hamilton Downtown graph for CO
Hamilton Mountain 30Hamilton Mountain graph for O3 5Hamilton Mountain graph for PM2.5 3.6Hamilton Mountain graph for NO2 0.2Hamilton Mountain graph for SO2  
Hamilton West 28Hamilton West graph for O3 5Hamilton West graph for PM2.5 5.2Hamilton West graph for NO2    
Kingston 28Kingston graph for O3 7Kingston graph for PM2.5 2.2Kingston graph for NO2    
Kitchener 30Kitchener graph for O3 5Kitchener graph for PM2.5 2.3Kitchener graph for NO2    
London 30London graph for O3 6London graph for PM2.5 5.6London graph for NO2    
Milton 29Milton graph for O3 6Milton graph for PM2.5 2.5Milton graph for NO2 0.2Milton graph for SO2  
Mississauga 31Mississauga graph for O3 5Mississauga graph for PM2.5 2.6Mississauga graph for NO2    
Newmarket 30Newmarket graph for O3 6Newmarket graph for PM2.5 1.5Newmarket graph for NO2    
North Bay 27North Bay graph for O3 3North Bay graph for PM2.5 0.5North Bay graph for NO2    
Oakville 31Oakville graph for O3 5Oakville graph for PM2.5 1.4Oakville graph for NO2    
Oshawa 32Oshawa graph for O3 4Oshawa graph for PM2.5 0.7Oshawa graph for NO2    
Ottawa Downtown 14Ottawa Downtown graph for O3 11Ottawa Downtown graph for PM2.5 11.4Ottawa Downtown graph for NO2    
Parry Sound 30Parry Sound graph for O3 1Parry Sound graph for PM2.5 1Parry Sound graph for NO2    
Peterborough 30Peterborough graph for O3 4Peterborough graph for PM2.5 0.5Peterborough graph for NO2    
Port Stanley 28Port Stanley graph for O3 8Port Stanley graph for PM2.5 1.9Port Stanley graph for NO2    
Sarnia 20Sarnia graph for O3 15Sarnia graph for PM2.5 4.5Sarnia graph for NO2 0.2Sarnia graph for SO2  
Sault Ste. Marie 23Sault Ste. Marie graph for O3 2Sault Ste. Marie graph for PM2.5 2.5Sault Ste. Marie graph for NO2 0.6Sault Ste. Marie graph for SO2  
St. Catharines 29St. Catharines graph for O3 5St. Catharines graph for PM2.5 3.8St. Catharines graph for NO2    
Sudbury 31Sudbury graph for O3 2Sudbury graph for PM2.5 0Sudbury graph for NO2 0.2Sudbury graph for SO2  
Thunder Bay 11Thunder Bay graph for O3 5Thunder Bay graph for PM2.5 22Thunder Bay graph for NO2    
Tiverton 30Tiverton graph for O3 6Tiverton graph for PM2.5      
Toronto Downtown 29Toronto Downtown graph for O3 6Toronto Downtown graph for PM2.5 5.7Toronto Downtown graph for NO2    
Toronto East 29Toronto East graph for O3 5Toronto East graph for PM2.5 2.4Toronto East graph for NO2    
Toronto North 28Toronto North graph for O3 5Toronto North graph for PM2.5 3.9Toronto North graph for NO2 0.4Toronto North graph for SO2  
Toronto West 25Toronto West graph for O3 5Toronto West graph for PM2.5 3.2Toronto West graph for NO2 0.1Toronto West graph for SO2 0.14Toronto West graph for CO
Windsor Downtown 4Windsor Downtown graph for O3 23Windsor Downtown graph for PM2.5 24Windsor Downtown graph for NO2 0Windsor Downtown graph for SO2 N/AWindsor Downtown graph for CO
Windsor West 3Windsor West graph for O3 24Windsor West graph for PM2.5 23.3Windsor 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.

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