SmogRank / World / South Korea / Chungcheongnam-do / January 2026

Most polluted cities in Chungcheongnam-do, South Korea, January 2026

14 cities in Chungcheongnam-do, South Korea ranked by their average PM2.5 over the 31 days. Worst: Seonghwan at 24.8 µg/m³, #249 of 2,593 cities in the world. Cleanest: Buyeo at 13.5. A city needs measurements on 70% of the days to be ranked.

About 160K people in these 12 cities breathed unhealthy air on an average day of January 2026.

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 85K 80K0
Every city in Chungcheongnam-do, South Korea ranked for January 2026 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
    85K
  2. 2Asan
    12.6K
  3. 3Boryeong
    12.2K
  4. 4Hongseong
    11.5K
  5. 5Gongju
    9.35K
  6. 6Nonsan
    5.66K
  7. 7Yesan
    5.09K
  8. 8Seosan
    4.79K
  9. 9Seonghwan
    4.72K
  10. 10Yŏnmu
    4.04K
  11. 11Tangjin
    3.17K
  12. 12Taesal-li
    2.24K
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, January 2026 · All cities in South Korea, January 2026 · Chungcheongnam-do now

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SmogRank, most polluted cities in Chungcheongnam-do, South Korea, PM2.5, January 2026, smogrank.com/kr/region/chungcheongnam-do/history/2026-01 (accessed 7 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.