SmogRank / World / Asia / South Korea / Sejong-si

Most polluted cities in Sejong-si, South Korea

1 measured city, last 30 days; 1 above the WHO 24-hour guideline. Worst: Sejong at 78.7 µg/m³, #61 in the world.

  1. 1Sejong 167
Good0–50
Moderate51–100
Sensitive groups101–150
Unhealthy151–200
Very unhealthy201–300
Hazardous301+

The US EPA's Air Quality Index for PM2.5 (2024 breakpoints). Show values as: µg/m³ · US AQI · India AQI · China AQI · European AQI · UK DAQI · Canada AQHI+. About the scales

Bad-air episodes in Sejong-si

Times when many cities around here had PM2.5 at twice their usual or more on the same days.

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SmogRank, most polluted cities in Sejong-si, South Korea, PM2.5, last 30 days to 2 Oct 2026, 11:00 UTC, smogrank.com/kr/region/sejong-si?w=30d.

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Updated 2026-10-02 11:07 UTC. Values are PM2.5 (fine particles), the median of each city's monitors, as the US AQI PM2.5 sub-index.