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 Month Chiang Mai Bangkok Phuket 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.
