SoloSquareGuides Meet people in Chiang RaiMeet people

City, Thailand

Air quality in Chiang Rai

Updated October 2026Sources
32PM2.5 µg/m³, yearly

Very polluted

The annual average PM2.5 in Chiang Rai was 32 µg/m³ in 2021, about 6.4 times the WHO guideline of 5 µg/m³. Crop burning and forest fires create heavy smoke Feb–Apr; AQI is often unhealthy and some days dangerous.

Key facts

Air quality across Thailand

PlacePM2.5Level
Udon Thani13 µg/m³Moderate
Phuket17 µg/m³Polluted
Patong17 µg/m³Polluted
Kanchanaburi17 µg/m³Polluted
Hat Yai17 µg/m³Polluted
Kata Beach17 µg/m³Polluted
Rawai17 µg/m³Polluted
Bangkok23 µg/m³Polluted
Chiang Mai26.5 µg/m³Very polluted
Khon Kaen30 µg/m³Very polluted
Chiang Rai32 µg/m³Very polluted

Quick answers

Is the air in Chiang Rai bad?

Very polluted: 32 µg/m³ of PM2.5 on average, 6.4× the WHO guideline. It's usually worst in Feb–Apr.

When is the air worst in Chiang Rai?

Crop burning and forest fires create heavy smoke Feb–Apr; AQI is often unhealthy and some days dangerous.

How does Chiang Rai compare with the rest of Thailand?

People in Thailand breathe 23 µg/m³ of PM2.5 on average (2023, World Bank/WHO), against 32 µg/m³ measured here.

More about Chiang Rai

Going to Chiang Rai solo?

SoloSquare is where travelers, nomads and locals in Chiang Rai meet up for small plans: coffee, dinners, walks and day trips. Join one, or start your own in a minute.

See plans in Chiang Rai

Sources

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 Spotted something out of date?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.