CHIANG MAI, THAILAND – Authorities in northern Thailand imposed a five-month ban on open burning to curb recurring PM2.5 smog during the 2026 dry season.
Province-wide ban on open fires
From 1 January to 31 May 2026, all forms of open burning across Chiang Mai province were prohibited, except in specially designated fuel management zones. The order aimed to limit the return of dense smog that typically blanketed the region in the dry months.
The directive was signed on 2 January 2026 by Ratthaphon Naradisorn, the governor of Chiang Mai, and set out fuel management and controlled-burn zones for the 2026 fiscal year. Outside these areas, open fires were completely banned, and within municipalities the burning of household waste, branches and leaves was also forbidden.
Health concerns from persistent haze
For years, Chiang Mai had struggled with severe smog, especially in the dry season when PM2.5 levels regularly rose to several times above recommended limits. The province repeatedly resorted to emergency measures to improve air quality.
Key sources of pollution were identified as open burning on open land, agricultural fires, burning of municipal waste and exhaust emissions from road traffic. Fine particles of PM2.5 were described as a serious burden on public health because they could penetrate deep into the lungs and were linked to respiratory and cardiovascular diseases.
Strict conditions for necessary burning
The current provincial order allowed only narrowly defined exceptions for essential fuel management. Such operations were permitted solely under strict conditions and prior approval.
Anyone seeking to conduct controlled fires had to register through the Fire-D/Burn Check system and obtain authorisation from the district centre for the prevention and resolution of forest fires, smog and fine dust. Approved activities were required to include firebreaks and clearly defined safeguards to prevent flames from spreading to surrounding areas.
National designation as pollution control zone
At national level, the National Environment Board classified the provinces of Chiang Mai, Chiang Rai, Lamphun and Mae Hong Son under code 2568 as pollution control zones. The designation was intended to enable additional measures to control, reduce and eliminate air pollutants during the critical period from February to May.
Authorities expected that the stricter framework would support enforcement of local bans and force closer cooperation between provincial, district and municipal levels. A report by Workpoint noted that officials planned to closely monitor both air quality and the effectiveness of enforcement in the coming months.
Rising PM2.5 readings ahead of peak season
Data from the Climate Change Data Centre at Chiang Mai University indicated that particulate levels were already increasing. At 10:00, the highest hourly PM2.5 reading of 74 micrograms per cubic metre was recorded in Sri Dong Yen subdistrict in Chai Prakan district.
This concentration was classified as an orange level and deemed hazardous to health. In Chiang Mai’s urban area, the Mae Hia subdistrict recorded a PM2.5 value of 52 micrograms per cubic metre.
Debate over whether ban marks turning point
Commentary accompanying the report pointed to recurring images, warnings and illnesses each year, while highlighting the tougher and earlier action taken by the province this season. It raised the question of whether a ban alone would be sufficient when economic interests, traditions and convenience stood in the way of change.
“Or is this precisely the moment when health finally has to matter more than habit?”
said Workpoint, media outlet.