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 to23 May 2023 That day's board

The worst cities for PM2.5 over the 7 days to 23 May 2023: Grande Prairie 212.0 µg/m³, Fort Saskatchewan 140.2 µg/m³ and Edmonton 135.7 µg/m³.

  1. 1Grande PrairieCanada212.0
  2. 2Fort SaskatchewanCanada140.2
  3. 3EdmontonCanada135.7
  4. 4Fort St. JohnCanada118.1
  5. 5BloemfonteinSouth Africa111.6
  6. 6EdsonCanada105.7
  7. 7Fort McMurrayCanada104.2
  8. 8Grand CentreCanada101.5
  9. 9St. AlbertCanada99.9
  10. 10LahorePakistan94.6
  11. 11Red DeerCanada94.1
  12. 12AirdrieCanada76.5
  13. 13Sherwood ParkCanada73.9
  14. 14CoyhaiqueChile73.2
  15. 15OsornoChile69.7
  16. 16Swift CurrentCanada68.8
  17. 17Puerto VarasChile62.2
  18. 18NacimientoChile62.1
  19. 19DhakaBangladesh61.8
  20. 20DelhiIndia60.7

+ 1,877 more cities, 58.6 µg/m³ and below

Not counted on this day, too few days measured: Quesnel since 21 May 2023, Hualpén since 19 May 2023, Zacapoaxtla since 8 May 2023 and 13 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.