SmogRank / History / City race
Cities in Canada, worst air first, day by day
Each measured city's average over the 30 days to every day since January 2023, worst first. Find your own city to follow it through the race, or keep to one country.
The worst cities in Canada for PM2.5 over the 30 days to 12 Aug 2025: Flin Flon 88.6 µg/m³, Prince Albert 50.5 µg/m³ and Fort McMurray 39.9 µg/m³.
- 1Flin FlonManitoba88.6
- 2Prince AlbertSaskatchewan50.5
- 3Fort McMurrayAlberta39.9
- 4SaskatoonSaskatchewan35.2
- 5EstevanSaskatchewan29.0
- 6NepeanOntario26.6
- 7ReginaSaskatchewan24.6
- 8Grand CentreAlberta24.3
- 9Sault Ste. MarieOntario22.6
- 10Swift CurrentSaskatchewan22.4
- 11NewmarketOntario22.3
- 12TorontoOntario22.2
- 13Parry SoundOntario21.9
- 14MiltonOntario21.5
- 15Sorel-TracyQuebec21.0
- 16BarrieOntario20.9
- 17BécancourQuebec20.8
- 18DorvalQuebec20.8
- 19L'Ancienne-LoretteQuebec20.6
- 20GranbyQuebec20.5
+ 94 more cities, 20.5 µg/m³ and below
Not counted on this day, too few days measured: Rouyn-Noranda since 12 Aug 2025.
Cities counted each day
A city's number is its average over the 30 days, shown only when 21 of them were measured (5 of 7 on the 7-day race), the same minimum as the 30- and 7-day boards. A city whose monitors go quiet fades out where it stood rather than sliding down, so a gap never reads as cleaner air. Some large countries are thin or missing because their monitors' licences don't allow reuse. How we rank.
Not covered: the government monitoring networks of China and Turkey, which publish only on their own websites; we are building the readers for them. Most cities there are missing from this board, not clean. Why.