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 24 Jul 2023: Fort St. John 40.2 µg/m³, Edmonton 40.0 µg/m³ and Fort McMurray 39.8 µg/m³.
- 1Fort St. JohnBritish Columbia40.2
- 2EdmontonAlberta40.0
- 3Fort McMurrayAlberta39.8
- 4Grande PrairieAlberta37.2
- 5SaguenayQuebec33.2
- 6North BayOntario32.6
- 7Fort SaskatchewanAlberta32.0
- 8QuesnelBritish Columbia28.2
- 9Prince GeorgeBritish Columbia27.1
- 10Greater SudburyOntario27.0
- 11Grand CentreAlberta24.2
- 12OttawaOntario23.5
- 13Red DeerAlberta22.8
- 14WindsorOntario22.4
- 15CornwallOntario21.4
- 16SarniaOntario21.2
- 17St. AlbertAlberta21.1
- 18Sault Ste. MarieOntario21.0
- 19ShawiniganQuebec20.3
- 20BrossardQuebec19.8
+ 81 more cities, 19.7 µg/m³ and below
Not counted on this day, too few days measured: Bécancour since 15 Jul 2023 and Rouyn-Noranda since 14 Jul 2023. Days missing from the source archive fall in this window, so fewer countries are counted.
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.