SmogRank / History / City race

Cities, 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 7 days to25 May 2023 That day's board

The worst cities for PM2.5 over the 7 days to 25 May 2023: Fort Saskatchewan 133.3 µg/m³, Grande Prairie 131.8 µg/m³ and Edmonton 126.7 µg/m³.

  1. 1Fort SaskatchewanCanada133.3
  2. 2Grande PrairieCanada131.8
  3. 3EdmontonCanada126.7
  4. 4Fort McMurrayCanada110.0
  5. 5Grand CentreCanada99.2
  6. 6St. AlbertCanada91.0
  7. 7CoyhaiqueChile88.0
  8. 8Fort St. JohnCanada85.6
  9. 9LahorePakistan79.9
  10. 10EdsonCanada79.1
  11. 11Red DeerCanada78.3
  12. 12Sherwood ParkCanada68.7
  13. 13Drayton ValleyCanada66.4
  14. 14BaghdadIraq66.0
  15. 15DhakaBangladesh61.4
  16. 16OsornoChile60.9
  17. 17JakartaIndonesia58.7
  18. 18HyderabadIndia58.1
  19. 19NacimientoChile57.2
  20. 20AirdrieCanada57.1

+ 1,725 more cities, 56.7 µg/m³ and below

Not counted on this day, too few days measured: Kampala since 24 May 2023, Thembisa since 24 May 2023, Bloemfontein since 24 May 2023 and 18 more cities.

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.