SmogRank / History / City race

Cities in South Korea, worst air first, day by day

Each measured city's average over the 30 days to every day since January 2024, worst first. Find your own city to follow it through the race, or keep to one country.

CountriesCities
The 30 days to9 Jan 2026 That day's board

The worst cities in South Korea for PM2.5 over the 30 days to 9 Jan 2026: Okcheon 25.6 µg/m³, Yeongju 25.5 µg/m³ and Seonghwan 25.1 µg/m³.

  1. 1OkcheonNorth Chungcheong25.6
  2. 2YeongjuGyeongsangbuk-do25.5
  3. 3SeonghwanChungcheongnam-do25.1
  4. 4PubalGyeonggi-do25.1
  5. 5SangjuGyeongsangbuk-do24.2
  6. 6HwadoGyeonggi-do24.1
  7. 7GumiGyeongsangbuk-do23.6
  8. 8KimjeJeollabuk-do23.3
  9. 9YeongdongNorth Chungcheong23.0
  10. 10WŏnjuGangwon-do22.9
  11. 11KinzanChungcheongnam-do22.9
  12. 12SejongSejong-si22.2
  13. 13CheorwonGangwon-do22.0
  14. 14Chinch'ŏnNorth Chungcheong21.9
  15. 15YeojuGyeonggi-do21.8
  16. 16ChungjuNorth Chungcheong21.7
  17. 17Cheongju-siNorth Chungcheong21.7
  18. 18Gyeongsan-siGyeongsangbuk-do21.4
  19. 19AsanChungcheongnam-do21.3
  20. 20GwangjuGyeonggi-do21.0

+ 120 more cities, 21.0 µg/m³ and below

30 days7 days
GoodModerateSensitive groupsUnhealthyVery unhealthyHazardousWHO 24-hour guideline, 15 µg/m³Fades where it stood: not counted that day

A city's number is its average over the 30 days, shown only when 21 of them were measured (5 of 7 on the 7-day race), the same minimum as the 30- and 7-day boards. A city whose monitors go quiet fades out where it stood rather than sliding down, so a gap never reads as cleaner air. Some large countries are thin or missing because their monitors' licences don't allow reuse. How we rank.

Not covered: the government monitoring networks of China and Turkey, which publish only on their own websites; we are building the readers for them. Most cities there are missing from this board, not clean. Why.