SmogRank / World / South Korea / Chungcheongnam-do / 2025

Most polluted cities in Chungcheongnam-do, South Korea, 2025

14 cities in Chungcheongnam-do, South Korea ranked by their average PM2.5 over the 365 days; 14 above the WHO annual guideline (5.0 µg/m³). Worst: Seonghwan at 22.6 µg/m³, #207 of 2,624 cities in the world. Cleanest: Taesal-li at 13.1. A city needs measurements on 70% of the days to be ranked.

About 97.6K people in these 12 cities breathed unhealthy air on an average day of 2025.

Ranked by people: each city's population times its share of unhealthy days, those with a daily mean over 35.4 µg/m³ (US AQI 101+). That is how many people living there breathed unhealthy air on an average day. Only cities measured at 2 or more places at least 3 km apart are ranked: one monitor shouldn't speak for a whole city. Population is the city itself, not its wider metro area.

← Cheonan 48.3K 40K0
Every city in Chungcheongnam-do, South Korea ranked for 2025 with monitors in two or more places, one column each, ranked by people breathing unhealthy air: height is people on an average day, colour its average. Point at it to read a city; tap to open it.
  1. 1Cheonan
    48.3K
  2. 2Asan
    11.6K
  3. 3Hongseong
    7.11K
  4. 4Boryeong
    6.71K
  5. 5Seonghwan
    5.5K
  6. 6Seosan
    3.78K
  7. 7Yesan
    3.47K
  8. 8Tangjin
    2.96K
  9. 9Nonsan
    2.85K
  10. 10Gongju
    2.79K
  11. 11Yŏnmu
    1.99K
  12. 12Taesal-li
    594
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

All cities in the world, 2025 · All cities in South Korea, 2025 · Chungcheongnam-do now

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SmogRank, most polluted cities in Chungcheongnam-do, South Korea, PM2.5, 2025, smogrank.com/kr/region/chungcheongnam-do/history/2025 (accessed 6 Oct 2026).

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You're welcome to reuse a single chart, image or figure with this citation and a link. Terms. Raw monitor readings in bulk are published by OpenAQ, under each provider's licence.