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 to31 May 2023 That day's board

The worst cities for PM2.5 over the 7 days to 31 May 2023: Baghdad 99.8 µg/m³, Nacimiento 88.1 µg/m³ and Osorno 81.1 µg/m³.

  1. 1BaghdadIraq99.8
  2. 2NacimientoChile88.1
  3. 3OsornoChile81.1
  4. 4DhakaBangladesh80.8
  5. 5HualpénChile75.4
  6. 6CuricóChile73.0
  7. 7San CarlosChile71.9
  8. 8Puerto VarasChile66.1
  9. 9ChillánChile64.3
  10. 10LinaresChile63.2
  11. 11LajaChile63.1
  12. 12Puerto MonttChile61.7
  13. 13TemucoChile60.5
  14. 14CoyhaiqueChile58.6
  15. 15SantiagoChile58.0
  16. 16Los ÁngelesChile56.8
  17. 17RengoChile55.9
  18. 18RancaguaChile55.2
  19. 19TalaganteChile53.3
  20. 20BeijingChina51.0

+ 1,662 more cities, the next at 50.8 µg/m³

Not counted on this day, too few days measured: Fort Saskatchewan since 29 May 2023, Jakarta since 28 May 2023, Thembisa since 27 May 2023 and 18 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.