Entry banned in 9 Mae Hong Son forest reserves as PM2.5 worsens

Mae Hong Son is facing a deepening environmental crisis as PM2.5 pollution has surged and a large number of hotspots have been detected.

In response, the province has imposed its strictest measures, banning people from entering nine national reserved forest areas covering seven districts from April 7 to 30, 2026, in a bid to tackle the root causes of wildfires.

Wildfire and PM2.5 situation in Mae Hong Son

The Mae Hong Son Provincial Office of Natural Resources and Environment has issued an order titled: “Prohibition on any person from setting fire to forests or carrying out any activity in national reserved forest areas.”

The move comes as the situation involving wildfires, haze and fine particulate matter (PM2.5) in the province has continued to worsen, with pollution levels persistently exceeding safety standards.

Authorities have detected a large number of hotspots, which are directly affecting public health. Most have been linked to human activity, such as lighting fires to collect forest products or burning waste material that later spreads into forest areas.

Nine forest reserve areas in seven districts under strict watch

The order covers national reserved forest areas in seven districts across Mae Hong Son province as follows:

• Mae Surin Forest: Khun Yuam district
• Left Bank of Mae Yuam Forest (lower section): Mae La Noi, Mae Sariang and Sop Moei districts
• Left Bank of Mae Yuam Forest (upper section): Khun Yuam and Mae La Noi districts
• Salawin Forest: Mae Sariang and Sop Moei districts
• Upper Left Bank of Mae Pai Forest: Pai district
• Right Bank of Mae Yuam Forest: Mae La Noi, Mae Sariang and Sop Moei districts
• Mae Ngao Forest and Mae Sampheng Forest: Khun Yuam and Mae La Noi districts
• Right Bank of Mae Pai Forest: Pang Mapha and Mueang Mae Hong Son districts
• Left Bank of Mae Pai Forest: Mueang Mae Hong Son district

Five key measures the public should know

To ensure the crackdown produces concrete results, the province has introduced the following measures:

• Temporary forest closure: All activities and the use of forest resources in national reserved forest areas are prohibited from April 7 to 30, 2026.
   
• Entry in necessary cases: Anyone who needs to enter must report to the kamnan (subdistrict headman), village headman or forestry authorities and obtain written permission. If a fire breaks out in an authorised area, the person granted entry will be presumed responsible.
   
• Tight checks on suspects: Officials will record the names of those entering forest areas without permission. Anyone found with suspicious behaviour or equipment that could cause a wildfire will face immediate legal action.
   
• Travel restrictions: Residents living in forest areas may use only the regular routes connecting villages.
   
• Cooperation in firefighting: Anyone who spots a forest fire is urged to immediately notify the kamnan, village headman, local administrative organisation or forestry authorities.

Penalties: up to 20 years in prison and a 2 million baht fine

Setting fire to forest areas in national reserved forests is an offence under the National Reserved Forest Act, BE 2507 (1964), specifically Sections 14 and 31. The penalties are as follows:

• General offence: imprisonment of 1 to 10 years and/or a fine of 20,000 to 200,000 baht
• If damage exceeds 25 rai: imprisonment of 4 to 20 years and/or a fine of 200,000 to 2 million baht

Members of the public can report forest fires by contacting local forestry authorities or informing community leaders in the area at any time, 24 hours a day, in an effort to help reduce the toxic haze crisis and protect Mae Hong Son’s forest resources.