SmogRank / Countries / Thailand / December 2025

Most polluted cities in Thailand, December 2025

5 cities in Thailand ranked by their average PM2.5 over the 31 days. Worst: Khlong Luang at 35.5 µg/m³, #209 of 2,360 cities in the world. Cleanest: Bang Pakong at 32.8. A city needs measurements on 70% of the days to be ranked.

  1. 1Khlong Luanglow-cost sensorsPathum Thani
    35.5
  2. 2Chiang Mailow-cost sensorsChiang Mai
    34.2
  3. 3Sai Mailow-cost sensorsBangkok
    33.7
  4. 4Bangkoklow-cost sensorsBangkok
    33.5
  5. 5Bang Pakonglow-cost sensorsChachoengsao
    32.8
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, December 2025 · Thailand now