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 to31 May 2023 That day's board

The worst cities for PM2.5 over the 30 days to 31 May 2023: Grande Prairie 87.6 µg/m³, Lahore 74.0 µg/m³ and Dhaka 71.3 µg/m³.

  1. 1Grande PrairieCanada87.6
  2. 2LahorePakistan74.0
  3. 3DhakaBangladesh71.3
  4. 4OsornoChile68.6
  5. 5NacimientoChile65.8
  6. 6DelhiIndia58.8
  7. 7LinaresChile58.8
  8. 8BaghdadIraq57.4
  9. 9CoyhaiqueChile55.8
  10. 10CuricóChile54.5
  11. 11Puerto VarasChile54.2
  12. 12SantiagoChile51.9
  13. 13Fort St. JohnCanada50.9
  14. 14RancaguaChile50.1
  15. 15LajaChile50.0
  16. 16San CarlosChile49.7
  17. 17TalaganteChile48.2
  18. 18HualquiChile48.1
  19. 19Fort McMurrayCanada47.7
  20. 20Fort SaskatchewanCanada47.5

+ 1,689 more cities, the next at 46.6 µg/m³

Not counted on this day, too few days measured: Kampala since 23 May 2023, Hualpén since 20 May 2023, Shenyang since 13 May 2023 and 38 more cities.

30 days7 days
GoodModerateUnhealthy for sensitive 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, Turkey and Iran, which publish only on their own websites. We are building the reader for China's network. The networks of Turkey and Iran don't answer requests from outside their countries, so we can't read them. Most cities there are missing from this board, not clean. Why.