Thailand PM2.5 through the year

One chart, three cities. Monthly PM2.5 profiles for Chiang Mai, Bangkok, and Phuket.
Chiang Mai peak
April · 82
µg/m³ PM2.5
Bangkok peak
February · 50
µg/m³ PM2.5
Phuket peak
March · 20
µg/m³ PM2.5
Chiang MaiBangkokPhuketWHO annual guideline · 5 µg/m³

Monthly PM2.5 data

MonthChiang MaiBangkokPhuket

What the comparison shows

Chiang Mai: by far the strongest seasonal swing, with a dramatic burning-season spike in March–April.

Bangkok: elevated in the cool dry season, especially November–February, but without Chiang Mai’s extreme spring peak.

Phuket: flatter and generally cleaner, helped by maritime airflow and the monsoon.

Chiang Mai uses 2024 monitoring-station monthly values. Bangkok uses monthly averages aggregated across 2019–2023. Phuket is an approximate comparative seasonal profile rather than a single official station-year series.