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 to25 Apr 2023 That day's board

The worst cities for PM2.5 over the 30 days to 25 Apr 2023: Mae Sai 256.4 µg/m³, Chiang Mai 126.7 µg/m³ and Dhaka 109.6 µg/m³.

  1. 1Mae SaiThailand256.4
  2. 2Chiang MaiThailand126.7
  3. 3DhakaBangladesh109.6
  4. 4LoeiThailand86.0
  5. 5KathmanduNepal78.9
  6. 6LahorePakistan70.7
  7. 7BamakoMali70.6
  8. 8SukhothaiThailand66.2
  9. 9UttaraditThailand65.7
  10. 10BeijingChina63.6
  11. 11Bueng KanThailand62.8
  12. 12PakxanLaos62.8
  13. 13TlaquepaqueMexico62.6
  14. 14DelhiIndia61.3
  15. 15Bang Khun ThianThailand57.0
  16. 16ShenyangChina56.3
  17. 17PhichitThailand55.4
  18. 18Ubon RatchathaniThailand52.5
  19. 19CoyhaiqueChile51.1
  20. 20HyderabadIndia50.5

+ 1,714 more cities, 49.7 µg/m³ and below

Not counted on this day, too few days measured: Bloemfontein since 25 Apr 2023, Chiang Rai since 25 Apr 2023, Sing Buri since 25 Apr 2023 and 34 more cities. Days missing from the source archive fall in this window, so fewer countries are counted.

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.