Northeast hardest hit as PM2.5 exceeds standard in many provinces
CAPM says PM2.5 has breached the standard in several regions, with the Northeast worst affected, while Bangkok and the South remain in the good range.
PM2.5 levels rose above the standard in several parts of Thailand on Wednesday, with the Northeast facing the most serious pollution, while Bangkok and the South remained in the good range, according to the Center for Air Pollution Mitigation (CAPM).
In its latest air quality report at 5pm on March 18, 2026, CAPM said dust levels above the standard were recorded across multiple regions, with the Northeast showing the most alarming readings.
Northeast records the worst pollution
The Northeast was the hardest-hit region, with PM2.5 levels ranging from 31.1 to 70.9 micrograms per cubic metre and exceeding the standard in most areas. The affected provinces were Bueng Kan, Nong Khai, Loei, Nakhon Phanom, Mukdahan, Khon Kaen, Kalasin, Maha Sarakham, Roi Et, Amnat Charoen, Yasothon, Ubon Ratchathani, Si Sa Ket, Buri Ram and Surin.
In the North, PM2.5 levels exceeded the standard in two provinces, Nan and Uttaradit, with readings ranging from 10.4 to 39.7 micrograms per cubic metre.
The Central and western regions recorded above-standard dust levels in one area, Saraburi, with readings of 15.6 to 43.9 micrograms per cubic metre.
By contrast, Bangkok and surrounding areas remained in the good range, with readings of 10.6 to 32.6 micrograms per cubic metre. The East also posted good air quality at 7.5 to 28.8 micrograms per cubic metre, while the South recorded very good air quality, with readings of 11.2 to 14.1 micrograms per cubic metre.
Dust outlook remains a concern in the North and Northeast
CAPM said air quality in Bangkok and surrounding areas, the Central and western regions, and the East was expected to improve during March 19-25, although some areas would still need monitoring.
The 17 northern provinces are expected to see PM2.5 levels rise on March 20-21, while the Northeast is forecast to worsen during March 19-24, with some locations still requiring close watch.
The South is expected to remain in good condition throughout the period.
Public urged to limit outdoor exposure
With dust levels in many provinces beginning to affect health, CAPM advised the public to monitor their health, cut back on time spent outdoors and wear protective equipment such as N95 masks when outside.
Vulnerable groups, including children, older people, pregnant women and those with underlying health conditions, were advised to avoid outdoor activities. Anyone experiencing symptoms such as coughing, breathing difficulties or eye irritation should seek medical advice immediately.
CAPM said the public could follow real-time air quality updates through the Air4Thai and AirBKK websites and mobile applications.
