SmogRank / History / City race

Cities in Thailand, 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 to14 Apr 2025 That day's board

The worst cities in Thailand for PM2.5 over the 30 days to 14 Apr 2025: Mae Sai 80.6 µg/m³, Nan 74.2 µg/m³ and Chiang Khong 69.4 µg/m³.

  1. 1Mae SaiChiang Rai80.6
  2. 2NanNan74.2
  3. 3Chiang KhongChiang Rai69.4
  4. 4Chiang RaiChiang Rai62.2
  5. 5Ubon RatchathaniUbon Ratchathani61.0
  6. 6LamphunLamphun60.5
  7. 7PhayaoPhayao58.6
  8. 8PhraePhrae56.0
  9. 9Chiang MaiChiang Mai54.5
  10. 10Mae SotTak51.3
  11. 11LoeiLoei51.0
  12. 12YasothonYasothon50.3
  13. 13SukhothaiSukhothai50.1
  14. 14Ban ChangRayong49.2
  15. 15KalasinKalasin48.9
  16. 16UttaraditUttaradit48.5
  17. 17Bueng KanBueng Kan48.1
  18. 18Chai NatChai Nat48.0
  19. 19Roi EtRoi Et45.0
  20. 20Amnat CharoenAmnat Charoen44.9

+ 65 more cities, 44.8 µg/m³ and below

Not counted on this day, too few days measured: Lampang since 12 Apr 2025, Khon Kaen since 12 Apr 2025 and Tha Bo since 14 Mar 2025.

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.