SmogRank / Countries / Thailand / August 2025

Most polluted cities in Thailand, August 2025

5 cities in Thailand ranked by their average PM2.5 over the 31 days. Worst: Chiang Mai at 9.8 µg/m³, #979 of 2,289 cities in the world. Cleanest: Bang Pakong at 4.3. A city needs measurements on 70% of the days to be ranked.

  1. 1Chiang Mailow-cost sensorsChiang Mai
    9.8
  2. 2Khlong Luanglow-cost sensorsPathum Thani
    9.1
  3. 3Bangkoklow-cost sensorsBangkok
    8.2
  4. 3Sai Mailow-cost sensorsBangkok
    8.2
  5. 5Bang Pakonglow-cost sensorsChachoengsao
    4.3
Good0–9.0
Moderate9.1–35.4
Sensitive groups35.5–55.4
Unhealthy55.5–125.4
Very unhealthy125.5–225.4
Hazardous225.5+

All cities in the world, August 2025 · Thailand now