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

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

14 cities in Chungcheongnam-do, South Korea ranked by their average PM2.5 over the 31 days. Worst: Seonghwan at 21.4 µg/m³, #237 of 2,771 cities in the world. Cleanest: Taesal-li at 12.1. A city needs measurements on 70% of the days to be ranked.

About 13.6K people in these 12 cities breathed unhealthy air on an average day of May 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.

← Asan 6.31K 6K0
Every city in Chungcheongnam-do, South Korea ranked for May 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. 1Asan
    6.31K
  2. 2Tangjin
    3.17K
  3. 3Seonghwan
    2.83K
  4. 4Yesan
    1.27K
  5. 5Cheonan
    0
  6. 6Hongseong
    0
  7. 6Yŏnmu
    0
  8. 8Nonsan
    0
  9. 9Seosan
    0
  10. 10Boryeong
    0
  11. 11Gongju
    0
  12. 12Taesal-li
    0
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, May 2025 · All cities in South Korea, May 2025 · Chungcheongnam-do now

Use this board

SmogRank, most polluted cities in Chungcheongnam-do, South Korea, PM2.5, May 2025, smogrank.com/kr/region/chungcheongnam-do/history/2025-05 (accessed 6 Oct 2026).

Download top 10 (PNG)

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.