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

Most polluted cities in Chungcheongnam-do, South Korea

14 measured cities, this year; 14 above the WHO annual guideline. Worst: Seonghwan at 22.7 µg/m³, #305 in the world.

About 111K people in these 12 cities breathed unhealthy air on an average day so far this year.

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.

Gyeonggi-do: 26 measured citiesGyeongsangbuk-do: 17 measured citiesChungcheongnam-do: 14 measured citiesDaejeon: 2 measured citiesGyeongsangnam-do: 12 measured citiesGangwon-do: 15 measured citiesJeollabuk-do: 13 measured citiesNorth Chungcheong: 7 measured cities#14 Buyeo: 12.4 µg/m³#13 Gongju: 14.2 µg/m³#12 Seosan: 14.8 µg/m³#11 Taesal-li: 15.3 µg/m³#10 Nonsan: 15.5 µg/m³#9 Boryeong: 16.8 µg/m³#8 Yŏnmu: 17.3 µg/m³#7 Cheonan: 17.5 µg/m³#6 Kinzan: 17.7 µg/m³#5 Hongseong: 18.7 µg/m³#4 Asan: 19.3 µg/m³#3 Yesan: 19.4 µg/m³#2 Tangjin: 19.6 µg/m³#1 Seonghwan: 22.7 µg/m³
Each dot is a measured city, coloured by its PM2.5; tap a dot to open the city.
← Cheonan 57.5K 50K0
Every measured city in Chungcheongnam-do, South Korea 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 57.5K
  2. 2Asan 12.7K
  3. 3Hongseong 8.78K
  4. 4Boryeong 6.83K
  5. 5Seonghwan 4.41K
  6. 6Yesan 4.28K
  7. 7Gongju 4K
  8. 8Tangjin 3.44K
  9. 9Nonsan 2.91K
  10. 10Seosan 2.9K
  11. 11Yŏnmu 2.2K
  12. 12Taesal-li 1.25K
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 Chungcheongnam-do

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 Chungcheongnam-do, South Korea, PM2.5, this year to 6 Oct 2026, 23:00 UTC, smogrank.com/kr/region/chungcheongnam-do?w=year.

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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.

Updated 2026-10-06 23:07 UTC. Values are PM2.5 (fine particles), the median of each city's monitors, as the US AQI PM2.5 sub-index.