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.

CountriesCities
The 30 days to9 Feb 2025 That day's board

The worst cities in Canada for PM2.5 over the 30 days to 9 Feb 2025: L'Ancienne-Lorette 11.4 µg/m³, Port Alberni 10.9 µg/m³ and Sorel-Tracy 10.3 µg/m³.

  1. 1L'Ancienne-LoretteQuebec11.4
  2. 2Port AlberniBritish Columbia10.9
  3. 3Sorel-TracyQuebec10.3
  4. 4Prince GeorgeBritish Columbia10.2
  5. 5CranbrookBritish Columbia10.1
  6. 6DuncanBritish Columbia10.0
  7. 7BécancourQuebec9.7
  8. 8QuesnelBritish Columbia9.7
  9. 9LangfordBritish Columbia9.6
  10. 10WindsorOntario9.4
  11. 11QuébecQuebec9.0
  12. 12ShawiniganQuebec8.9
  13. 13VictoriaBritish Columbia8.6
  14. 14KamloopsBritish Columbia8.5
  15. 15TorontoOntario8.5
  16. 16Trois-RivièresQuebec8.5
  17. 17HamiltonOntario8.4
  18. 18SmithersBritish Columbia8.4
  19. 19VernonBritish Columbia8.2
  20. 20BrossardQuebec8.0

+ 92 more cities, 8.0 µg/m³ and below

Not counted on this day, too few days measured: Brooklin since 24 Jan 2025, Gatineau since 19 Jan 2025, Nepean since 19 Jan 2025 and Harewood since 17 Dec 2024.

30 days7 days
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 readers for them. Most cities there are missing from this board, not clean. Why.