What is the air quality in Seoul?

Seoul, South Korea has an annual US AQI of 76 (Polluted) and average PM2.5 of 21.9 µg/m³, ranking #3574 of 5856 cities. Main pollutant: PM2.5.

What is the cleanest month in Seoul?

September is typically the cleanest month (AQI 59) and March the most polluted (AQI 90).

Where does Seoul's air quality data come from?

PM2.5: 1998–2026 (monitors 2015–2026, satellite 1998–2014; 2025–2026 provisional). Measured by government monitoring stations. Full sources are on the methodology page.

Seoul, South Korea — Air Quality & Clean City Guide 2026

Seoul Air Quality Data

Global rank	City	Continent	AQI	PM2.5
3574	Seoul, South Korea	Asia	AQI 76	PM2.5 21.9 µg/m³