health
Chiang Mai PM2.5 reaches 409 μg/m3, air quality declared extremely dangerous
On April 4 Chiang Mai recorded extremely dangerous PM2.5 levels of 409 μg/m3 at Nakornping Hospital, triggering health warnings and urgent advice to stay indoors.
Apr 4th 2026 · Thailand
Insights
- PM2.5 readings at Nakornping Hospital in Mae Rim reached 409 micrograms per cubic metre at 9am on April 4.
- Dense haze reduced visibility and obscured nearby buildings in parts of Chiang Mai.
- Patients, especially those with heart or respiratory disease, reported breathing difficulties.
- Authorities advise avoiding outdoor activity, wearing fitted N95 masks, sealing windows and using air purifiers.
- Officials say the episode reflects recurring seasonal haze in northern Thailand and calls for sustained solutions.
Sources
- Blood clots, burning eyes: Pollution chokes north Thailand www.straitstimes.com
- Blood clots and burning eyes as pollution chokes north Thailand www.japantimes.co.jp
- PM2.5 levels in Chiang Mai reaches ‘extremely dangerous’ levels, visibility plummets www.straitstimes.com