SmogRank / World / Thailand / Bangkok / March 2025

Most unhealthy days in Bangkok, Thailand, March 2025

3 cities in Bangkok, Thailand ranked by their share of unhealthy days over the 31 days. The most unhealthy days: Nong Khaem, Thailand, 13 of 30 measured days. A city needs measurements on 70% of the days to be ranked.

Bangkok has 13 cities ranked over the last 30 days, but only 3 here: most of its monitors have no readings for March 2025 in OpenAQ's archive, where ours come from, or too few to rank. Cities missing from this board weren't clean, just not measured.

Ranked by unhealthy days: the share of each city's measured days with a daily mean over 35.4 µg/m³ (US AQI 101+), Unhealthy for Sensitive Groups or worse on the US EPA's scale. Ties go to the higher average.

← Nong Khaem 43% 40%0
Every city in Bangkok, Thailand ranked for March 2025, one column each, ranked by unhealthy days: height is the share of its measured days that were unhealthy, colour its average. Point at it to read a city; tap to open it.
  1. 1Nong Khaem
    13 of 30
  2. 2Bangkok
    10 of 31
  3. 3Bang Kapi
    9 of 29
Good0–50
Moderate51–100
Sensitive groups101–150
Unhealthy151–200
Very unhealthy201–300
Hazardous301+

The US EPA's Air Quality Index for PM2.5 (2024 breakpoints). Show values as: µg/m³ · US AQI · India AQI · China AQI · European AQI · UK DAQI · Canada AQHI+. About the scales

All cities in the world, March 2025 · All cities in Thailand, March 2025 · Bangkok now

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SmogRank, most polluted cities in Bangkok, Thailand, by unhealthy days, PM2.5, March 2025, smogrank.com/th/region/bangkok/history/2025-03?by=days (accessed 7 Oct 2026).

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You're welcome to reuse a single chart, image or figure with this citation and a link. Terms. Raw monitor readings in bulk are published by OpenAQ, under each provider's licence.