BANGKOK — 21 April 2026, Air pollution exceeded safety limits in 38 provinces across Thailand on Monday, with the north remaining in a critical condition and eight provinces recording hazardous levels, authorities said.
The Pollution Control Department reported at 07:00 that 24-hour average PM2.5 levels ranged from 13.4 to 132.0 micrograms per cubic metre, above the national standard of 37.5 in many areas.
Northern provinces were the worst affected, with readings between 38.7 and 132.0, and eight provinces, Chiang Rai, Chiang Mai, Mae Hong Son, Lamphun, Nan, Phayao, Sukhothai and Phitsanulok are classified as red zones posing health risks.
The highest level was recorded in Huai Khon subdistrict of Nan’s Chaloem Phra Kiat district at 132.0 micrograms per cubic metre.
In the northeast, levels ranged from 21.8 to 73.8, while the central and western regions recorded 25.5 to 73.2, with most areas exceeding standards.
Air quality in the east and south remained largely within safe limits, with readings between 13.4 and 30.2, and 15.4 to 23.7 respectively.
In Bangkok and surrounding areas, pollution exceeded the standard at one monitoring station, with levels between 17.7 and 38.7.
Authorities advised the public to limit outdoor activities and use protective measures, especially in high-risk areas, and to seek medical attention if experiencing symptoms.
