Monitoring Air Quality

To support the Air Quality Health Index (AQHI), the Ministry monitors up to 6 common pollutants at each of the 39 stations across the provincial AQHI network, including:

Ontario Air Quality Health Index Monitoring Network

Pollutants are monitored at each station.
CITY/TOWN O3 PM2.5 NO2 SO2 CO TRS
WINDSOR DOWNTOWN X X X X X -
WINDSOR WEST X X X X - X
CHATHAM X X X - - -
SARNIA X X X X - X
GRAND BEND X X X - - -
LONDON X X X - - -
PORT STANLEY X X X - - -
TIVERTON X X X - - -
BRANTFORD X X X - - -
KITCHENER X X X - - -
ST. CATHARINES X X X - - -
GUELPH X X X - - -
HAMILTON DOWNTOWN X X X X X X
HAMILTON MOUNTAIN X X X X - -
TORONTO DOWNTOWN X X X - - -
TORONTO EAST X X X - - -
TORONTO NORTH X X X - - -
TORONTO WEST X X X X X -
BURLINGTON X X X - - -
OAKVILLE X X X - - -
OSHAWA X X X - - -
BRAMPTON X X X - - -
MISSISSAUGA X X X X - -
BARRIE X X X - - -
NEWMARKET X X X - - -
PARRY SOUND X X X - - -
DORSET X X - - - -
OTTAWA DOWNTOWN X X X X - -
OTTAWA CENTRAL X X X - - -
PETAWAWA X X - - - -
KINGSTON X X X - - -
BELLEVILLE X X X - - -
MORRISBURG X X - - - -
CORNWALL X X X - - -
PETERBOROUGH X X X - - -
THUNDER BAY X X X - - -
SAULT STE. MARIE X X X X - X
NORTH BAY X X X - - -
SUDBURY X X X X - -

For current AQHI information, please visit www.airqualityontario.com, www.ec.gc.ca/cas-aqhi, or call the AQHI Reporting System line at: (416) 246-0411 in the Toronto area or 1 (800) 387-7768 toll free. For AQHI Information in French, call 1 (800) 221-8852