Chiang mai: Chiang Mai has been ranked as the city with the worst air quality in the world. The city's pollution levels are alarmingly high, reaching levels 20 times greater than what is considered normal, and affecting the health of all residents.

According to Thai News Agency, the IQAir website, which specializes in air quality rankings, reported that on the morning of March 30, 2026, Chiang Mai, Thailand, had an Air Quality Index (AQI) of 205, placing it at the top of the list for the most polluted major cities globally. This level of air pollution poses severe health risks to everyone in the area.

The list of the top five cities with the poorest air quality includes Yangon, Myanmar, with an AQI of 186; Delhi, India, with an AQI of 175; Kampala, Uganda, at 160; and Hanoi, Vietnam, with an AQI of 158. These figures highlight a significant global issue of air pollution affecting urban centers around the world.

According to air quality data from the Climate Change Information Center at Chiang Mai University, all 111 air quality monitoring stations across Chiang Mai province reported PM2.5 levels in the hazardous red zone. Chiang Dao district was particularly affected, with the Ban Pang Mayao Sub-district Health Promotion Hospital recording an hourly PM2.5 level of 905 micrograms per cubic meter at 11:00 AM, far exceeding standard safety levels.