Is the air quality good in Ulaanbaatar?
On May 21, 2026, at 10:50 PM (local time), air quality in Ulaanbaatar, Mongolia, is poor with an AQI of 200, which falls within the "unhealthy" range.
These conditions pose serious health risks, particularly for children, the elderly, and those with respiratory or cardiovascular conditions.
Air quality is dynamic and, like the weather, can change frequently. Ulaanbaatar is ranked the most polluted major city in the world on Thursday night.
Click here for a real-time air quality map of Ulaanbaatar.
While the air quality conditions today are poor, it is important to note that the average PM2.5 concentration in 2025 for Ulaanbaatar was 17.9 µg/m³. This corresponds to an AQI of 63, which falls into the “moderate” category and was 3.5 times the WHO annual guideline of 5 µg/m³.
Ulaanbaatar, Mongolia ranked as the most polluted major city on May 21, 2026, 10:50 PM (local time). Source: IQAir.
When will air quality improve in Ulaanbaatar?
Air quality in Ulaanbaatar is forecasted to improve by tomorrow evening.
Hourly air quality forecast for Ulaanbaatar, Mongolia on May 21, 2026. Source: IQAir.
Seasonal improvements typically occur during warmer months when household heating demand decreases and atmospheric conditions allow pollutants to disperse more effectively.
Air quality map of Ulaanbaatar, Mongolia on May 21, 2026. Source: IQAir.
What is causing poor air quality in Ulaanbaatar?
Several factors continue to contribute to poor air quality in Ulaanbaatar, including:
- Rapid urbanization and population growth
- Vehicle emissions from an aging vehicle fleet
- Construction dust and secondary aerosols
- Geographic conditions caused by the city’s valley location surrounded by mountains
Recent research found that warm-season PM concentrations have increased annually despite lower heating demand, highlighting the increasing impact of transportation and urban development on air quality (1).
Studies also show that NO2 levels in residential districts are significantly influenced by vehicle emissions, especially from older vehicles and heavy traffic corridors (2).
Ulaanbaatar’s surrounding mountains and valley geography can trap pollutants near the surface, allowing poor air quality to persist even during warmer months (3).
How can I protect myself from poor air quality?
- Get a free air quality app for real-time air quality alerts and forecasts.
- Shut doors and windows and set the HVAC to recirculate mode.
- Contribute to your community’s outdoor air quality data.
- Stay indoors when air quality is poor; if you do need to go outdoors, wear a KN95/FFP2 mask.
- Run a high-performance air purifier to filter particles, gases, and other pollutants.
