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 28 Jan 2023: Nong Khaem 40.4 µg/m³, Bang Khun Thian 37.8 µg/m³ and Samut Sakhon 36.6 µg/m³.
- 1Nong KhaemBangkok40.4
- 2Bang Khun ThianBangkok37.8
- 3Samut SakhonSamut Sakhon36.6
- 4Bang KapiBangkok33.0
- 5Mueang NonthaburiNonthaburi32.5
- 6Khlong LuangPathum Thani32.5
- 7BangkokBangkok32.2
- 8Phra PradaengSamut Prakan25.1
Days missing from the source archive fall in this window, so fewer countries are counted.
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.