PM2.5 in Chiang Rai by district
18 districts in Chiang Rai. Choose one to see PM2.5 now and its history.
Districts ranked by PM2.5 now
Loading latest values
Values come from the station nearest to each district and update hourly.
PM2.5 statistics for Chiang Rai, Jun 2025 to Jun 2026
Monthly average
Districts by yearly average
| District | Average | Days over limit |
|---|---|---|
| Chiang Khong | 31.8 | 56 |
| Chiang Saen | 31.8 | 56 |
| Mae Fa Luang | 31.8 | 56 |
| Mae Sai | 31.8 | 56 |
| Pa Daet | 26.7 | 53 |
| Wiang Pa Pao | 26.7 | 53 |
| Doi Luang | 23.5 | 40 |
| Khun Tan | 23.5 | 40 |
| Mae Chan | 23.5 | 40 |
| Mae Lao | 23.5 | 40 |
| Mae Suai | 23.5 | 40 |
| Mueang Chiang Rai | 23.5 | 40 |
| Phan | 23.5 | 40 |
| Phaya Mengrai | 23.5 | 40 |
| Thoeng | 23.5 | 40 |
| Wiang Chai | 23.5 | 40 |
| Wiang Chiang Rung | 23.5 | 40 |
| Wiang Kaen | 23.5 | 40 |
All districts
Frequently asked questions
How many districts in Chiang Rai can I check for PM2.5?
18 districts. Each one shows the reading from its nearest Air4Thai station, with the distance to that station.
At what PM2.5 level should I wear a mask?
Above 25 µg/m³ at-risk groups should wear a surgical mask outdoors for long periods. From 37.6 to 75 the air starts to affect health and an N95 mask is advised. Above 75 avoid outdoor activity.
How often is the data updated?
Readings come from the Pollution Control Department's Air4Thai feed and are refreshed every hour.
What is AQI and how is it different from PM2.5?
AQI (Air Quality Index) is a single number calculated from several pollutants: PM2.5, PM10, ozone, carbon monoxide, nitrogen dioxide and sulphur dioxide. The pollutant with the worst value in that hour sets the AQI. The Pollution Control Department's bands are 0 to 25 excellent, 26 to 50 good, 51 to 100 moderate, 101 to 200 unhealthy for sensitive groups and 201 and above unhealthy. PM2.5 is one pollutant only: the concentration of particles up to 2.5 microns across, measured in µg/m³. This site uses PM2.5 as its main value and for card colours, and shows AQI as supporting data, so the two can fall in different bands.