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 to19 Apr 2024 That day's board

The worst cities for PM2.5 over the 30 days to 19 Apr 2024: N'Djamena 159.9 µg/m³, Chiang Khong 98.7 µg/m³ and Ban Houakhoua 98.7 µg/m³.

  1. 1N'DjamenaChad159.9
  2. 2Chiang KhongThailand98.7
  3. 3Ban HouakhouaLaos98.7
  4. 4Mae SaiThailand97.5
  5. 5KathmanduNepal94.0
  6. 6DhakaBangladesh87.2
  7. 7Chiang MaiThailand78.4
  8. 8LahorePakistan72.1
  9. 9PhayaoThailand72.0
  10. 10NanThailand70.9
  11. 11DelhiIndia69.7
  12. 12LampangThailand69.2
  13. 13LamphunThailand68.5
  14. 14Chiang RaiThailand63.9
  15. 15KalasinThailand63.5
  16. 16Ubon RatchathaniThailand62.9
  17. 17Tha BoThailand62.7
  18. 18VientianeLaos62.7
  19. 19UttaraditThailand61.7
  20. 20BeijingChina61.2

+ 2,437 more cities, 61.1 µg/m³ and below

Not counted on this day, too few days measured: Pljevlja since 26 Mar 2024, Tetovo since 20 Mar 2024, Gostivar since 20 Mar 2024 and Tlaquepaque since 10 Mar 2024.

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.