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 27 Jun 2023: Rouyn-Noranda 62.4 µg/m³, North Bay 40.8 µg/m³ and Greater Sudbury 38.4 µg/m³.
- 1Rouyn-NorandaQuebec62.4
- 2North BayOntario40.8
- 3Greater SudburyOntario38.4
- 4SaguenayQuebec35.0
- 5Grande PrairieAlberta34.1
- 6OttawaOntario31.2
- 7Fort McMurrayAlberta27.9
- 8Sault Ste. MarieOntario27.0
- 9Prince AlbertSaskatchewan25.7
- 10Labrador CityNewfoundland and Labrador25.6
- 11BellevilleOntario25.0
- 12EdmontonAlberta24.7
- 13KingstonOntario23.8
- 14Parry SoundOntario23.1
- 15WindsorOntario22.6
- 16Fort SaskatchewanAlberta22.5
- 17LondonOntario22.4
- 18St. ThomasOntario22.4
- 19EdsonAlberta22.1
- 20SaskatoonSaskatchewan22.1
+ 86 more cities, the next at 22.0 µg/m³
Not counted on this day, too few days measured: Fort St. John since 15 Jun 2023 and Brandon since 30 May 2023.
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 reader for China's network. Turkey's network doesn't answer requests from outside the country, so we can't read it. Most cities there are missing from this board, not clean. Why.