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 10 Nov 2025: Duncan 7.9 µg/m³, Windsor 7.8 µg/m³ and Castlegar 7.7 µg/m³.
- 1DuncanBritish Columbia7.9
- 2WindsorOntario7.8
- 3CastlegarBritish Columbia7.7
- 4Port AlberniBritish Columbia7.6
- 5VernonBritish Columbia7.5
- 6CranbrookBritish Columbia7.3
- 7QuesnelBritish Columbia7.3
- 8EdmontonAlberta6.7
- 9SmithersBritish Columbia6.5
- 10KelownaBritish Columbia6.3
- 11CalgaryAlberta6.1
- 12HarewoodBritish Columbia6.1
- 13Prince GeorgeBritish Columbia6.0
- 14TerraceBritish Columbia5.8
- 15KamloopsBritish Columbia5.7
- 16EstevanSaskatchewan5.5
- 17BarrieOntario5.4
- 18LangfordBritish Columbia5.4
- 19Campbell RiverBritish Columbia5.3
- 20Fort SaskatchewanAlberta5.3
+ 93 more cities, 4.9 µg/m³ and below
Not counted on this day, too few days measured: Sorel-Tracy since 30 Oct 2025, Yellowknife since 29 Oct 2025, Creston since 17 Oct 2025 and Williams Lake since 4 Oct 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.