SmogRank / History / City race

Cities in Japan, worst air first, day by day

Each measured city's average over the 30 days to every day since January 2023, worst first. Find your own city to follow it through the race, or keep to one country.

CountriesCities
The 30 days to21 Dec 2023 That day's board

The worst cities in Japan for PM2.5 over the 30 days to 21 Dec 2023: Chikusei 16.4 µg/m³, Kasaoka 14.9 µg/m³ and Shimo-tsuma 14.5 µg/m³.

  1. 1ChikuseiIbaraki16.4
  2. 2KasaokaOkayama14.9
  3. 3Shimo-tsumaIbaraki14.5
  4. 4KurashikiOkayama13.8
  5. 5KazoSaitama13.3
  6. 6JōsōIbaraki13.2
  7. 7FukuyamaHiroshima13.0
  8. 8TsuchiuraIbaraki12.8
  9. 9MiyakonojōMiyazaki12.7
  10. 10NodaChiba12.5
  11. 11KōnosuSaitama12.5
  12. 12ChikugoFukuoka12.5
  13. 13HayashimaOkayama12.4
  14. 14TamanoOkayama12.3
  15. 15SōjaOkayama12.3
  16. 16ŌmutaFukuoka12.2
  17. 17FujisatoMie12.2
  18. 18YatomiAichi12.2
  19. 19IgusaSaitama12.1
  20. 20GyōdaSaitama12.1

+ 485 more cities, 12.1 µg/m³ and below

Not counted on this day, too few days measured: Nagai since 13 Dec 2023, Sano since 1 Dec 2023, Yachiyo since 16 Nov 2023 and Nago since 23 Oct 2023.

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.