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 to8 Jul 2026 That day's board

The worst cities in Thailand for PM2.5 over the 30 days to 8 Jul 2026: Bang Na 18.5 µg/m³, Kanchanaburi 17.2 µg/m³ and Khon Kaen 16.7 µg/m³.

  1. 1Bang NaBangkok18.5
  2. 2KanchanaburiKanchanaburi17.2
  3. 3Khon KaenKhon Kaen16.7
  4. 4Bueng KumBangkok16.1
  5. 5Khan Na YaoBangkok15.9
  6. 6Khlong LuangPathum Thani15.8
  7. 7Ban Talat BuengChon Buri15.5
  8. 8MukdahanMukdahan15.4
  9. 9Khlong Sam WaBangkok14.8
  10. 10Saphan SungBangkok14.3
  11. 11Phra PradaengSamut Prakan14.2
  12. 12Mae SaiChiang Rai14.0
  13. 13RayongRayong14.0
  14. 14Nong KhaemBangkok14.0
  15. 15Ban Samae DamBangkok14.0
  16. 16Lat KrabangBangkok13.7
  17. 17RatchaburiRatchaburi13.0
  18. 18KalasinKalasin12.8
  19. 19LamphunLamphun12.7
  20. 20Nakhon RatchasimaNakhon Ratchasima12.5

+ 49 more cities, 11.9 µg/m³ and below

Not counted on this day, too few days measured: Nakhon Pathom since 8 Jul 2026, Si Maha Phot since 7 Jul 2026, Bang Bo District since 6 Jul 2026 and 7 more cities.

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.