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Air quality in Ontario
Air quality index (AQI) and PM2.5 air pollution in Ontario
LIVE AQI CITY RANKING
Real-time Ontario
Most polluted city ranking
| # | city | US AQI |
|---|---|---|
| 1 | Vaughan | 41 |
| 2 | Milton | 38 |
| 3 | Bluewater | 37 |
| 4 | London | 33 |
| 5 | Sarnia | 33 |
| 6 | Thunder Bay | 33 |
| 7 | Tiverton | 31 |
| 8 | Markham | 30 |
| 9 | Belleville | 29 |
| 10 | Grand Bend | 29 |
(local time)
SEE WORLD AQI RANKINGAIR QUALITY DATA CONTRIBUTORS
96 Contributors
See all
LIVE AQI CITY RANKING
Real-time Ontario
Cleanest city ranking
| # | city | US AQI |
|---|---|---|
| 1 | Brockville | 8 |
| 2 | Coldwater | 8 |
| 3 | Fort Erie | 8 |
| 4 | Dorset | 12 |
| 5 | Kingston | 12 |
| 6 | St. Catharines | 12 |
| 7 | Burlington | 13 |
| 8 | Owen Sound | 13 |
| 9 | Almonte | 16 |
| 10 | Quinte West | 16 |
(local time)
SEE WORLD AQI RANKING
3D animated air pollution map
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Unhealthy for sensitive groups
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The latest air quality news and resources.
Ontario air quality data attribution
96Contributors
- Hamilton Air Monitoring Network - HAMN
9 stations
- Township of SNNF
1 station
4 Government Contributors
- DGEC - Greensville
1 station
- Electric Vehicle Council of Ottawa
1 station
- EVCO
1 station
National Air Pollution Surveillance Program2 stations
4 Non-profit organization Contributors
MikoAirOne1 station
- Anonymous
1 station
- Jim Guillet
1 station
- bsumm
1 station
Chris Fournier1 station
Slyyy1 station
JackB1 station
- Shawn K
1 station
Christopher Trevors1 station
- Anonymous
1 station
Nichols Family1 station
- Bruce Buckley
1 station
Graydon1 station
- IQAir Lab
1 station
Anonymous1 station
CS3 stations
- VB
1 station
- randalljhoward
1 station
- **
1 station
- Bijan
1 station
- Libby
1 station
- Mark Douglas Wessel
1 station
- JayDee
1 station
Me1 station
- Keevabay
1 station
25 Individual Contributors
63 Anonymous contributors63 stations
63 Anonymous Contributors
Which is the most polluted city in Ontario?
- Experimental Lakes 45
- Vaughan 41
- Pickle Lake 40
- Milton 38
- Bluewater 37
- Algoma 36
- Bonner Lake 33
- London 33
- Sarnia 33
- Thunder Bay 33
- Cornwall 32
- Innisfil 31
- Newmarket 31
- Tiverton 31
- Markham 30
- Belleville 29
- Egbert 29
- Grand Bend 29
- Kirkland Lake 28
- North Bay 28
- Orillia 28
- Port Stanley 28
- Richmond Hill 28
- Sault Ste Marie 28
- Sudbury 28
- Hamilton 27
- Renfrew 27
- Windsor 27
- Oakville 26
- Ottawa 26
- Brampton 25
- Brantford 25
- Guelph 25
- Kitchener 25
- Mississauga 24
- Parry Sound 24
- Woodstock 24
- Oshawa 23
- Toronto 23
- Uxbridge 23
- Ajax 21
- Cambridge 21
- Niagara on the Lake 21
- Peterborough 21
- Sioux Narrows 21
- Niagara Falls 20
- Scarborough 19
- Wellington County 19
- Chatham 17
- Timmins 17
- Almonte 16
- Quinte West 16
- Waterloo 16
- Burlington 13
- Owen Sound 13
- Dorset 12
- Kingston 12
- St. Catharines 12
- Brockville 8
- Coldwater 8
- Fort Erie 8
- Amherstburg 4
- Ancaster 4
- Angus 4
- Arnprior 4
- Atikokan 4
- Aylmer 4
- Bancroft 4
- Barrie 4
- Bells Corners 4
- Binbrook 4
- Blyth 4
- Bourget 4
- Bracebridge 4
- Brant 4
- Camlachie 4
- Carleton Place 4
- Casselman 4
- Clarence-Rockland 4
- Cobourg 4
- Collingwood 4
- Concord 4
- Deep River 4
- Delaware 4
- Deseronto 4
- Dorchester 4
- Dryden 4
- Ear Falls 4
- East York 4
- Elliot Lake 4
- Englehart 4
- Espanola 4
- Etobicoke 4
- Fort Frances 4
- Gananoque 4
- Goderich 4
- Gravenhurst 4
- Greater Napanee 4
- Greenstone 4
- Hanover 4
- Hawkesbury 4
- Hearst 4
- Hornepayne 4
- Huntsville 4
- Huron East 4
- Ingersoll 4
- Iroquois Falls 4
- Kapuskasing 4
- Keswick 4
- Kincardine 4
- Lambton Shores 4
- Lindsay 4
- Little Current 4
- Marathon 4
- Mattawa 4
- Midland 4
- Minden Hills 4
- Morrisburg 4
- Napanee Downtown 4
- Neebing 4
- Nepean 4
- Nestor Falls 4
- Norfolk County 4
- North Perth 4
- North York 4
- Omemee 4
- Orangeville 4
- Paris 4
- Pembroke 4
- Perth 4
- Petawawa 4
- Petrolia 4
- Pickering 4
- Picton 4
- Port Colborne 4
- Powassan 4
- Prescott 4
- Prince Edward 4
- Rayside-Balfour 4
- Red Lake 4
- Shelburne 4
- Simcoe 4
- Skatepark 4
- Smiths Falls 4
- South Huron 4
- South River 4
- St. Thomas 4
- Stratford 4
- Temiskaming Shores 4
- Thessalon 4
- Thorold 4
- Tobermory 4
- Walpole Island 4
- Wasaga Beach 4
- Welland 4
- Wendover 4
- Willowdale 4
- Wingham 4
AQI US, Metric