SmogRank / Countries / Thailand / September 2025

Most polluted cities in Thailand, September 2025

5 cities in Thailand ranked by their average PM2.5 over the 30 days. Worst: Khlong Luang at 11.1 µg/m³, #349 of 2,426 cities in the world. Cleanest: Bang Pakong at 7.3. A city needs measurements on 70% of the days to be ranked.

  1. 1Khlong Luanglow-cost sensorsPathum Thani
    11.1
  2. 2Sai Mailow-cost sensorsBangkok
    11.0
  3. 3Bangkoklow-cost sensorsBangkok
    9.8
  4. 4Chiang Mailow-cost sensorsChiang Mai
    8.9
  5. 5Bang Pakonglow-cost sensorsChachoengsao
    7.3
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, September 2025 · Thailand now

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SmogRank, most polluted cities in Thailand, PM2.5, September 2025, smogrank.com/th/history/2025-09 (accessed 2 Oct 2026).

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