Is the air quality good in Seoul?
On May 2, 2026, at 11:00 PM (local time), air quality in Seoul, South Korea is unhealthy for sensitive groups, with an Air Quality Index of 115.
Air quality is impacted by emissions, transboundary pollution, and secondary pollutant formation, with seasonal factors like dust transport and photochemical reactions further worsening conditions (1).
Air quality is dynamic and, like the weather, can change frequently. Seoul ranked 4th among the most polluted major cities in the world on Saturday night (local time).
Poor air quality is impacting cities across South Korea, including Busan, Cheonan, Daegu, Daejeon, Gwangju, Gwangyang, and Incheon.
Click here for a real-time air quality map of Seoul.
While the current air quality is poor, it is notable that the average PM2.5 concentration in 2025 for Seoul was 17.9 µg/m³, corresponding to an AQI of 63 (“moderate”), and was 3.5 times the WHO annual guideline of 5 µg/m³.
Seoul, South Korea ranked as the 4th most polluted major city on May 2, 2026 at 11 PM PT. Source: IQAir.
When will air quality improve in Seoul?
Air quality is forecasted to improve into a moderate range by tomorrow, with gradual long-term improvements expected as emission controls continue.
Hourly air quality forecast for Seoul, South Korea on May 2, 2026. Source: IQAir.
Sustained progress will depend on:
- Stronger emission control policies and cleaner energy adoption
- Reduced vehicle emissions
- Regional cooperation to limit transboundary pollution
Seasonal factors like monsoon-driven dispersion and lower activity levels may also bring temporary relief, though consistent improvement may take time due to complex pollution sources (2).
Air quality map of Seoul, South Korea on May 9, 2026. Source: IQAir.
What is causing poor air quality in Seoul?
Poor air quality in East Asian urban regions is caused by a combination of local emissions and regional influences.
- Vehicular emissions: A major source of NO₂ and PM2.5, especially in cities like Seoul
- Industrial activities: Contribute to particulate matter and gaseous pollutants
- Coal burning: Particularly significant in Beijing during winter heating seasons
- Transboundary pollution: Dust storms and pollutants transported from neighboring regions
- Secondary pollutant formation: Chemical reactions in the atmosphere forming ozone and fine particles
- Agricultural emissions: Ammonia from livestock contributes to particulate formation
Meteorological conditions such as temperature inversions and low wind speeds can trap pollutants near the surface, worsening air quality episodes (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.
