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 30 days to23 Sep 2023 That day's board

The worst cities for PM2.5 over the 30 days to 23 Sep 2023: Fort McMurray 70.2 µg/m³, Puerto Varas 62.9 µg/m³ and Osorno 61.5 µg/m³.

  1. 1Fort McMurrayCanada70.2
  2. 2Puerto VarasChile62.9
  3. 3OsornoChile61.5
  4. 4DushanbeTajikistan61.2
  5. 5Grande PrairieCanada58.3
  6. 6DhakaBangladesh53.6
  7. 7CoyhaiqueChile53.6
  8. 8EdmontonCanada53.3
  9. 9PeshawarPakistan52.7
  10. 10Prince AlbertCanada51.6
  11. 11NacimientoChile49.8
  12. 12LahorePakistan49.6
  13. 13Tha BoThailand49.1
  14. 14Grand CentreCanada48.2
  15. 15SaskatoonCanada45.8
  16. 16ReginaCanada45.4
  17. 17JakartaIndonesia45.3
  18. 18Fort St. JohnCanada45.2
  19. 19Fort SaskatchewanCanada43.5
  20. 20La UniónChile43.3

+ 2,189 more cities, 42.4 µg/m³ and below

Not counted on this day, too few days measured: Alexandria since 22 Sep 2023, Ash Shīḩānīyah since 4 Sep 2023, Linares since 4 Sep 2023 and 3 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.