Northern Thailand chokes under severe PM2.5 as hotspots persist

PM2.5 pollution remained at high levels across many parts of Thailand on April 2, 2026, with the North and Northeast continuing to bear the brunt of the air quality crisis, according to the Center for Air Pollution Mitigation (CAPM) under the Pollution Control Department.

In its air quality report issued at 12pm, CAPM said the overall situation remained worrying in several areas, particularly in the North, where many provinces were recorded in the red zone.

North remains hardest hit by toxic haze

The provinces in the North found to have red-level PM2.5 pollution were Chiang Rai, Chiang Mai, Mae Hong Son, Lampang, Lamphun, Nan, Phrae, Phayao, Tak, Uttaradit, Sukhothai, Phitsanulok, Kamphaeng Phet and Nakhon Sawan.

In the Northeast, most areas were in the orange zone, although some provinces also recorded red-level pollution, including Nong Khai, Bueng Kan, Nakhon Phanom and Ubon Ratchathani.

CAPM said PM2.5 levels in the North ranged from 53.4 to 326.3 micrograms per cubic metre, while the Northeast recorded 33.1 to 103.6 micrograms per cubic metre.

In the Central Plains and West, levels ranged from 21.3 to 54.1 micrograms per cubic metre. The East recorded 15.7 to 34.3 micrograms per cubic metre, the South 12.6 to 24.3 micrograms per cubic metre, and Bangkok and its surrounding areas 16.3 to 33.3 micrograms per cubic metre.

Hotspot data for April 1 showed that Thailand recorded a total of 1,971 hotspots, of which 1,416, or 72%, were found in forest areas. The provinces with the highest numbers of hotspots were Mae Hong Son, Tak, Chiang Mai, Nan and Lampang.

Despite a decline in hotspot numbers both inside and outside Thailand, CAPM said PM2.5 levels in the North remained persistently high because prevailing winds were still blowing from the west and south-west into the country, bringing pollution from both domestic and transboundary sources.

The agency also warned that air ventilation rates in northern provinces are expected to weaken between April 3 and 5, which could further intensify the haze situation.

Authorities step up firefighting and anti-burning efforts

Government agencies are continuing to integrate manpower to accelerate fire detection and suppression efforts, while also deploying aircraft and unmanned technology, including drones, to improve access to fires in steep and hard-to-reach areas.

Authorities also appealed to the public to refrain from all forms of burning in order to reduce PM2.5 pollution and protect public health.

People who spot open burning or forest fires are urged to call 1362, the hotline of the Department of National Parks, Wildlife and Plant Conservation, 1567, the Damrongtham Centre of the Interior Ministry, or 1784, the Department of Disaster Prevention and Mitigation.

CAPM also advised the public to take care of their health, wear face masks and protective gear when going outdoors if necessary, and follow guidance from the Public Health Ministry.

The agency said people can monitor the dust situation through the Air4Thai website or the Air4Thai application.