CHIANG MAI –Once again Chiang Mai Province facing dangerous PM2.5 air pollution, and this time the situation is getting worse fast. Thick white smoke now hangs over much of the city as PM2.5 levels climb and visibility drops.
At the same time, officials are rushing to respond after 158 wildfire hotspots were found across the province.
The sharp rise shows how quickly the yearly burning season has intensified. During this period, dry weather, farm burning, and forest fires combine to fill the air with fine dust.
Because Chiang Mai sits in a basin surrounded by mountains, that pollution often gets trapped close to the ground. Residents say the smell of smoke is strong, and health officials warn that the risk is immediate, especially for children, older adults, and people with existing health issues.
158 Wildfires Push Conditions Downhill Fast
New satellite images show a major jump in wildfire activity. On March 24, authorities recorded 158 wildfires in 15 districts across Chiang Mai province. That figure is nearly five times higher than the 33 hotspots reported one day earlier. The districts with the most fires include:
- Mae Taeng(29 hotspots)
- Chiang Dao(28 hotspots)
- Doi Saket(14 hotspots)
- Mae Wangand Samoeng(11 each)
- Hang Dong(10 hotspots)
Since January 1, the province has logged a total of 967 hotspots. That number shows how hard it has been to control the problem, even with prevention efforts already in place. Because the weather remains hot and dry, and rain has arrived late, fires have spread faster, especially in steep mountain areas that are hard to reach.
Meanwhile, white smoke has spread over much of Chiang Mai city. It drifts down from nearby mountains and stays in place because temperature inversions often trap polluted air inside the basin.
At one air monitoring station in Chang Phueak subdistrict, in Mueang district, PM2.5 reached 38.8 µg/m³ by early afternoon. That reading matched an AQI of 104, which is considered unhealthy for sensitive groups. In Hod district’s Hang Dong area, PM2.5 climbed even higher to 58.7 µg/m³, with an AQI of 157, which falls in the unhealthy range.
Those levels are above Thailand’s national 24-hour safety limit of 37.5 µg/m³. As a result, officials say the province is edging closer to a serious air quality crisis. Without strong winds or heavy rain, conditions could keep getting worse.
Emergency Teams Step Up Ground and Air Operations
The Chiang Mai Haze and Wildfire Situation Command Centeris now working nonstop with district offices, national agencies, and disaster response teams. Crews are focusing on ground work, such as building firebreaks and patrolling risk areas. At the same time, air support is being used for fires burning in remote mountain zones.
Officials have also asked the Ministry of Natural Resources and Environment for helicopter support. These aircraft are being sent to collect and drop water over active fires, especially in places like Sri Lanna National Park, where steep slopes make access by foot nearly impossible. Provincial disaster teams have already used helicopters in districts such as San Sai to help contain fires and assist teams on the ground.
Aerial water drops give crews a faster way to slow fires before they spread more smoke into already polluted air. Still, the command center says air operations alone are not enough. The broader response also depends on quicker fire detection, tougher action against illegal burning, and stronger help from local communities.
Chiang Rai Also Feels the Impact as Haze Spreads Across the North
The smoke is not stopping at Chiang Mai’s borders. Nearby Chiang Rai province is also seeing poorer air quality, although pollution levels change by area and by hour.
Recent data shows PM2.5 often staying in the 30 to 50 µg/m³ range. In many urban areas, including Mueang Chiang Rai, that has pushed AQI readings into the “unhealthy for sensitive groups” category, with some hourly spikes reaching 130 or more.
Like Chiang Mai, Chiang Rai is dealing with smoke from local forest fires, farm burning, and haze moving through valleys from nearby areas. Because northern Thailand’s geography connects these provinces so closely, smoke in one place can quickly affect another. So, the problem has become regional, not just local.
Public health agencies are warning residents to take the pollution seriously. PM2.5 particles are so small that they can move deep into the lungs and even enter the bloodstream. Because of that, officials are urging people to cut exposure as much as possible.
The health department says:
- Sensitive groups, including children, older adults, pregnant women, and people with heart or lung disease, should stay indoors and limit outside activity when AQI rises above 100.
- Everyoneshould wear a well-fitted N95 or PM2.5-rated maskwhen going outdoors, especially in the morning and evening, when pollution often gets worse.
- Common symptoms already reported include irritated eyes, sore throats, nasal discomfort, coughing, and skin rashes in people with allergies.
- Anyone with shortness of breath, chest pain, or severe symptoms should get medical care right away.
Hospitals in both Chiang Mai and Chiang Rai have reported more patients with breathing problems. In addition, officials recommend using air purifiers indoors, keeping windows closed, avoiding outdoor exercise, and checking real-time AQI through apps and government monitoring stations.
Long exposure during the burning season, which usually runs from February through April, can raise the risk of asthma flare-ups, bronchitis, heart problems, and weaker lung function in children.
Bigger Causes and What Comes Next
Northern Thailand’s haze problem is tied mainly to biomass burning. That includes clearing crop waste, slash-and-burn farming, and forest fires. Weather patterns then make the problem worse by holding smoke close to the ground. On top of that, haze drifting across borders from neighboring countries adds another layer to an already difficult situation.
Although the first part of 2026 had been less severe than some past years, the latest spike in fire hotspots shows the season is far from over. Officials say steady rainfall in April or May will likely be the main factor that clears the air and lowers pollution levels.
For now, residents and tourists are being told to follow official updates, take health warnings seriously, and support anti-burning efforts. The command center is continuing daily checks and may increase its response, including more aircraft, if conditions keep worsening.
At this point, the thick white smoke over Chiang Mai stands as a clear sign that short-term action is not enough. Lasting progress will depend on better land management, cleaner farming methods, and stronger cooperation across the region to protect both public health and the environment.
