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 8 Jun 2026: Ban Talat Bueng 24.7 µg/m³, Khon Kaen 20.8 µg/m³ and Mae Sai 19.7 µg/m³.
- 1Ban Talat BuengChon Buri24.7
- 2Khon KaenKhon Kaen20.8
- 3Mae SaiChiang Rai19.7
- 4KanchanaburiKanchanaburi19.0
- 5Si Maha PhotPrachin Buri18.7
- 6MukdahanMukdahan18.1
- 7Khlong LuangPathum Thani18.0
- 8Bang NaBangkok17.9
- 9Khan Na YaoBangkok17.6
- 10Nakhon RatchasimaNakhon Ratchasima16.7
- 11Ubon RatchathaniUbon Ratchathani16.5
- 12Khlong Sam WaBangkok16.5
- 13KalasinKalasin16.4
- 14Phra PradaengSamut Prakan16.3
- 15Maha SarakhamMaha Sarakham16.1
- 16Samut SakhonSamut Sakhon16.0
- 17RatchaburiRatchaburi15.9
- 18Lat KrabangBangkok15.8
- 19LamphunLamphun15.6
- 20Bueng KumBangkok15.6
+ 59 more cities, 15.5 µg/m³ and below
Not counted on this day, too few days measured: Sangkhla Buri since 5 Jun 2026, Nan since 29 May 2026, Nakhon Luang since 17 May 2026 and 3 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.