Chiang Mai set for disaster declaration after 4 days of soaring PM2.5

TUESDAY, MARCH 31, 2026

Deputy Governor Siwakorn Buapong said Mueang Na in Chiang Dao has recorded PM2.5 above 125µg/m³ for four straight days, with a disaster declaration possible tomorrow.

  • Chiang Mai is preparing to declare a disaster zone in its Mueang Na subdistrict after PM2.5 pollution levels exceeded 125 µg/m³ for four consecutive days.
  • The official declaration will be triggered if the hazardous pollution levels persist for a fifth consecutive day, meeting the criteria set by the Ministry of Finance.
  • In response to the crisis, authorities plan to deploy mobile medical units, issue public health alerts, and distribute face masks to residents in the hardest-hit areas.

Chiang Mai is preparing to tighten controls on toxic PM2.5 pollution.

Siwakorn Buapong, Deputy Governor of Chiang Mai Province, said PM2.5 levels in Mueang Na subdistrict, Chiang Dao District, have risen above 125 micrograms per cubic metre for four consecutive days.

The province is set to consider declaring the area a disaster-stricken zone tomorrow, while mobile medical units will be deployed on April 1, 2026.

Siwakorn Buapong, Deputy Governor of Chiang Mai Province, spoke about the crisis caused by fine particulate matter (PM2.5) in the area on March 30, saying the province is considering declaring a disaster-stricken area and an area eligible for emergency disaster assistance, focusing on the hardest-hit locations at the subdistrict and village levels.

Criteria for declaring a toxic haze disaster area

Under Ministry of Finance regulations, the province can declare a disaster area when the following conditions are met:

  • PM2.5 levels must exceed 125 micrograms per cubic metre (µg/m³).
  • The concentration must remain at that level for five consecutive days.

Current situation: Mueang Na subdistrict in Chiang Dao District has already recorded critical pollution levels for four consecutive days.

If the situation does not improve tomorrow (March 31, 2026), it will immediately meet the threshold for a disaster declaration.

Areas under watch and relief measures

Although Chiang Dao District is at a critical level, the deputy governor stressed that the situation in Mueang Chiang Mai District has not yet met the criteria.

Any declaration will focus only on clearly affected areas rather than the whole province, to ensure precision in budget management and relief efforts.

Three urgent measures to protect the public:

  1. Cell Broadcast alerts: Messages will be sent immediately to residents in “red” areas, advising them to avoid outdoor activities and wear face masks.
  2. Support for vulnerable groups: The provincial public health office and village health volunteers have been instructed to distribute face masks and speed up the establishment of “Dust-Free Rooms” in communities.
  3. Mobile medical units: On April 1, 2026, the province will mobilise mobile medical teams to treat respiratory illnesses and provide advice to people in high-risk areas.

How to protect yourself from PM2.5 today

For Chiang Mai residents in areas where the Air Quality Index (AQI) is in the red zone, the advice is as follows:

  • Wear an N95 mask when going outdoors.
  • Keep doors and windows tightly closed, and use an air purifier if available.
  • Watch for unusual symptoms such as coughing, chest tightness or eye irritation. If symptoms do not improve, seek medical attention or contact local village health volunteers.