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 30 days to28 May 2023 That day's board

The worst cities in Canada for PM2.5 over the 30 days to 28 May 2023: Grande Prairie 88.1 µg/m³, Fort St. John 51.1 µg/m³ and Edson 46.4 µg/m³.

  1. 1Grande PrairieAlberta88.1
  2. 2Fort St. JohnBritish Columbia51.1
  3. 3EdsonAlberta46.4
  4. 4Fort McMurrayAlberta45.1
  5. 5Fort SaskatchewanAlberta44.0
  6. 6EdmontonAlberta41.7
  7. 7Grand CentreAlberta34.6
  8. 8Red DeerAlberta33.2
  9. 9St. AlbertAlberta31.7
  10. 10Prince AlbertSaskatchewan28.8
  11. 11AirdrieAlberta28.4
  12. 12Sherwood ParkAlberta25.2
  13. 13CalgaryAlberta24.6
  14. 14SaskatoonSaskatchewan24.1
  15. 15Swift CurrentSaskatchewan23.8
  16. 16Prince GeorgeBritish Columbia19.8
  17. 17QuesnelBritish Columbia16.9
  18. 18ReginaSaskatchewan16.9
  19. 19LethbridgeAlberta14.6
  20. 20Medicine HatAlberta14.0

+ 84 more cities, the next at 13.4 µg/m³

GoodModerateSensitive groupsUnhealthyVery unhealthyHazardousWHO 24-hour guideline, 15 µg/m³Fades where it stood: not counted that 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.