CHIANG MAI, THAILAND – The northern city recorded the worst air quality in the world as PM2.5 levels in the Chiang Dao district reached alarming highs.
Worst air quality worldwide
On the morning of 27 March 2026, it was reported that air quality in the municipality of Chiang Mai was ranked number one among the worst cities worldwide. The US.AQI air quality index measured 184 micrograms per cubic meter.
The concentration of PM2.5 particles was 102.2 micrograms per cubic meter, posing a serious threat to public health. According to the report, these levels exceeded the annual guidelines of the World Health Organization by 20.4 times.
Air quality measurements
During an air quality check in Chiang Mai at 8:00 a.m., six monitoring points recorded values above the standard level of 37.5 micrograms per cubic meter. The readings ranged from 49 to 183 micrograms per cubic meter.
The highest measured PM2.5 value was 183.6 micrograms per cubic meter. Additional measurements showed that the Chiang Mai Provincial Government Center recorded 87.3 micrograms per cubic meter.
Health risks and recommendations
Health authorities advised residents to protect themselves with PM2.5 masks when leaving buildings. They recommended limiting time spent outdoors, especially during strenuous activities.
People with existing health risks were urged to exercise particular caution. They were told to seek medical attention immediately if they experienced abnormal symptoms such as coughing or breathing difficulties.
Regional differences in air quality
Air quality measurements varied across different parts of Chiang Mai. At Debaratana Wechanukul Hospital, PM2.5 levels reached 73.9 micrograms per cubic meter.
By comparison, the provincial electricity authority office in Hot district recorded a value of 72.5 micrograms per cubic meter, which was also described as worrying.
Public reactions and measures
The public reacted with concern to the alarming air quality figures. Many residents called on the authorities to take faster action to improve the air.
There were also discussions about long-term solutions to reduce air pollution in the region in a sustainable way.
Your view
The original report invited readers to share their opinions on the situation in Chiang Mai and on the response by the authorities. It encouraged people to discuss possible solutions and to exchange their experiences with the current air quality.
“What do you think of the current air quality in Chiang Mai? Do you believe that the authorities are taking sufficient action to improve the situation?”
said Chiang Mai News, inviting public feedback.