City, Thailand
Air quality in Chiang Mai
Very polluted
The annual average PM2.5 in Chiang Mai was 26.5 µg/m³ in 2021, about 5.3 times the WHO guideline of 5 µg/m³. Burning season makes PM2.5 among the world's worst in Feb–Apr, peaking in March; many nomads leave for the coast.
Key facts
- PM2.5: 26.5 µg/m³ yearly average (2021). Measured at Chiang Mai.
- PM10: 42 µg/m³ (2021).
- Nitrogen dioxide: 22.4 µg/m³ (2021), mostly from traffic.
- Worst months: Feb–Apr.
Air quality across Thailand
| Place | PM2.5 | Level |
|---|---|---|
| Udon Thani | 13 µg/m³ | Moderate |
| Phuket | 17 µg/m³ | Polluted |
| Patong | 17 µg/m³ | Polluted |
| Kanchanaburi | 17 µg/m³ | Polluted |
| Hat Yai | 17 µg/m³ | Polluted |
| Kata Beach | 17 µg/m³ | Polluted |
| Rawai | 17 µg/m³ | Polluted |
| Bangkok | 23 µg/m³ | Polluted |
| Chiang Mai | 26.5 µg/m³ | Very polluted |
| Khon Kaen | 30 µg/m³ | Very polluted |
| Chiang Rai | 32 µg/m³ | Very polluted |
Quick answers
Is the air in Chiang Mai bad?
Very polluted: 26.5 µg/m³ of PM2.5 on average, 5.3× the WHO guideline. It's usually worst in Feb–Apr.
When is the air worst in Chiang Mai?
Burning season makes PM2.5 among the world's worst in Feb–Apr, peaking in March; many nomads leave for the coast.
How does Chiang Mai compare with the rest of Thailand?
People in Thailand breathe 23 µg/m³ of PM2.5 on average (2023, World Bank/WHO), against 26.5 µg/m³ measured here.
More about Chiang Mai
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Sources
- WHO Ambient Air Quality Database
- WHO air quality guidelines (2021)
- Live air quality map (WAQI)
- Chiang Mai International Airport (Airports of Thailand)
- Bolt Chiang Mai
- Punspace
- Chiang Mai Ram Hospital
Annual averages are measured values reported to the WHO; check a live map for today's air. Compiled and reviewed by SoloSquare. How we compile and score this. Spotted something out of date? Tell us.