CHIANG MAI — Air quality in Chiang Mai province has deteriorated sharply, with thick haze blanketing the city as forest fires surge across much of the upper North, pushing pollution levels to among the worst in the world.

Pollution Control Department Warns of Rising PM2.5 Until Mid-January

Satellite data on Thursday morning detected 235 hotspots in 17 provinces, with Lampang recording 60 and Phrae 33, the highest numbers in the region. Chiang Mai reported one hotspot in Hot district, though the city itself remains heavily affected by smoke drifting from surrounding areas.

PM2.5 Levels Exceed Standards

The Pollution Control Department (PCD) confirmed that levels of particulate matter 2.5 micrometres and less in diameter (PM2.5) have exceeded safe standards at all monitoring stations in Chiang Mai. Readings at 11 a.m. on Thursday showed 24-hour averages ranging from 51.2 to 69.4 microgrammes per cubic metre (µg/m³), well above the national limit of 37.5 µg/m³.

Air Quality Index (AQI) values reached unhealthy to hazardous levels between 137 and 185, posing significant health risks to residents. AirVisual, a global monitoring application, ranked Chiang Mai’s air quality the fifth worst in the world, with an AQI of 172.

Crisis Warning

Officials warned that without rain forecast by the Thai Meteorological Department (TMD), the northern province could see PM2.5 readings reach crisis levels on Friday. Vulnerable groups, including children, the elderly, and those with respiratory conditions, are urged to take precautions.

Chiang Mai, THAILAND

Haze heavily shrouds a forest fire control officer using a leaf blower at Thailand’s Mae Ping National Park, Chiang Mai, one of the country’s top 10 severely burned protected areas.
Credit : Sayan Chuenudomsavad pic.twitter.com/wm8maODVH0

— Argo 🍀 (@ArgoHydra) March 3, 2026

Health Preparations

Deputy Chiang Mai Governor Siwa Thamikanon has instructed health agencies to prepare for a surge in respiratory patients, ensuring medical supplies, equipment, and dust-free rooms are available. Chiang Mai currently maintains 2,004 clean rooms across hospitals, schools, government offices, and childcare centres to accommodate those most vulnerable to air pollution effects.

Fire Control Efforts

Authorities have deployed patrol teams to monitor forest reserves and national parks, setting up checkpoints to prevent and control fires. Helicopters have been dispatched to drop water on steep mountain blazes in Lamphun province, where fires have spread for several days, contributing to the deteriorating air quality across the region.

Regional Severity

The situation is particularly severe in Lampang, Lamphun, and Phrae, where PM2.5 levels have reached the “unhealthy” red zone, with readings as high as 94.1 µg/m³. The concentration of hotspots in these areas suggests agricultural burning and forest fires are combining to create a regional air quality crisis.

Samut Prakan has the world’s 9th worst air quality

Public Advisories

Residents are urged to wear masks when outdoors, avoid outdoor activities, and report forest fires to local authorities. With northern Thailand facing one of its most severe smog seasons in years, officials stress that community cooperation is vital to controlling the crisis and preventing further deterioration of air quality.

-Thailand News (TN)