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.
The worst cities in Thailand for PM2.5 over the 30 days to 11 Jun 2026: Ban Talat Bueng 23.2 µg/m³, Khon Kaen 20.4 µg/m³ and Mae Sai 20.1 µg/m³.
- 1Ban Talat BuengChon Buri23.2
- 2Khon KaenKhon Kaen20.4
- 3Mae SaiChiang Rai20.1
- 4Bang NaBangkok17.8
- 5KanchanaburiKanchanaburi17.7
- 6MukdahanMukdahan17.6
- 7Si Maha PhotPrachin Buri17.2
- 8Khlong LuangPathum Thani17.1
- 9Khan Na YaoBangkok16.6
- 10Khlong Sam WaBangkok15.5
- 11LamphunLamphun15.4
- 12Phra PradaengSamut Prakan15.4
- 13Bueng KumBangkok15.1
- 14RatchaburiRatchaburi15.0
- 15Nakhon RatchasimaNakhon Ratchasima14.9
- 16Lat KrabangBangkok14.9
- 17Samut SakhonSamut Sakhon14.7
- 18RayongRayong14.6
- 19Saphan SungBangkok14.6
- 20Maha SarakhamMaha Sarakham14.4
+ 58 more cities, 14.4 µg/m³ and below
Not counted on this day, too few days measured: Chiang Khong since 10 Jun 2026, Sangkhla Buri since 5 Jun 2026, Nan since 29 May 2026 and 4 more cities.
Cities counted each 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.