SmogRank / Countries / Thailand / January 2026

Most polluted cities in Thailand, January 2026

4 cities in Thailand ranked by their average PM2.5 over the 31 days. Worst: Khlong Luang at 55.3 µg/m³, #34 of 2,047 cities in the world. Cleanest: Chiang Mai at 33.3. A city needs measurements on 70% of the days to be ranked.

  1. 1Khlong Luanglow-cost sensorsPathum Thani
    55.3
  2. 2Sai Mailow-cost sensorsBangkok
    48.9
  3. 3Bangkoklow-cost sensorsBangkok
    43.4
  4. 4Chiang Mailow-cost sensorsChiang Mai
    33.3
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, January 2026 · Thailand now