Southeast Asia Air Quality Alert

Is the air quality good in Southeast Asia?

On April 17, 2026, air quality across Southeast Asia remains poor, with some of the major cities experiencing air quality in the "unhealthy" to "very unhealthy" range and high PM2.5 concentrations, posing serious health risks to residents, especially children and the elderly.

By 2:00 PM (local time, UTC+7), several urban centers have recorded AQI readings between 100 and 300, prompting health warnings. Residents are advised to limit outdoor activity, keep windows closed, wear masks when outside, and use air purifiers indoors.

While conditions remain variable, Southeast Asia’s average PM2.5 levels in 2025 continued to exceed WHO guidelines across the region. Indonesia recorded around 30 µg/m³, about six times the guideline, while Vietnam reached 29.7 µg/m³, or 5.9 times higher. Myanmar and Laos measured 4.7 and 4.5 times the limit, respectively, while Thailand and Cambodia were each about 3.6 times above, underscoring persistent regional air quality challenges.

Air quality map of Southeast Asia and neighboring countries as of 2:00 PM (local time) on April 17, 2026. Source: IQAir.

When will the air quality improve in Southeast Asia?

As of April 17, 2026, several major cities across Southeast Asia are reporting poor air quality. Some of the affected cities include:

Air quality conditions can change rapidly throughout the day. For a complete, real-time overview of pollution levels nationwide, see Southeast Asia air quality map.

Chiang Mai, Hanoi and Yangon ranked among the most polluted major cities globally, as of 2:00 PM (local time) on April 17, 2026. Source: IQAir.

When will air quality improve in Southeast Asia?

Conditions usually begin to improve in late April as weather patterns shift and the rainy season approaches, with rainfall and increased atmospheric mixing helping to disperse smoke particles and reduce PM2.5 concentrations.

By Songkran in mid-April, air quality in northern Thailand typically clears, though the pattern of "fine one day, hazardous the next" persists until monsoon rains provide more sustained relief.

For maritime Southeast Asia, the dry season runs through October, meaning improvement there depends on the onset of the northeast monsoon. Lasting regional progress requires coordinated cross-border emission controls and a transition away from open burning practices (1).

What is causing poor air quality in Southeast Asia?

Southeast Asia experiences two distinct burning seasons each year, with mainland countries including Thailand, Myanmar, Laos, Cambodia, and Vietnam affected from November through May, while more equatorial maritime nations including Indonesia and Malaysia face peak fire activity from June through October (2).;

Biomass burning accounts for approximately 48% of annual average PM2.5 concentrations across mainland Southeast Asia, with forest fires, shrubland fires, and crop residue burning peaking in March when monthly average PM2.5 reaches 45 µg/m³.

Indonesia is the major contributor to transboundary haze across the region, as combustion of biomass and organic peat soil generates large volumes of carbonaceous fine particles that are carried by prevailing winds into Malaysia, Thailand, Singapore, Vietnam, and neighboring countries. Urban sources including vehicle emissions, coal-fired power generation, and industrial activity add to the pollution burden year-round (3).