SmogRank / History / City race

Cities, 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 to18 Jul 2023 That day's board

The worst cities for PM2.5 over the 30 days to 18 Jul 2023: Coyhaique 126.6 µg/m³, Nacimiento 84.5 µg/m³ and Hualpén 79.5 µg/m³.

  1. 1CoyhaiqueChile126.6
  2. 2NacimientoChile84.5
  3. 3HualpénChile79.5
  4. 4OsornoChile78.2
  5. 5Puerto VarasChile76.5
  6. 6DushanbeTajikistan67.4
  7. 7LajaChile66.2
  8. 8TemucoChile61.1
  9. 9CuranilahueChile61.0
  10. 10Puerto MonttChile55.5
  11. 11San CarlosChile55.4
  12. 12LinaresChile54.6
  13. 13ChillánChile53.2
  14. 14RancaguaChile52.7
  15. 15Los ÁngelesChile52.2
  16. 16Puerto AysénChile51.3
  17. 17TalcahuanoChile50.7
  18. 18La UniónChile50.4
  19. 19RengoChile50.3
  20. 20SantiagoChile48.1

+ 1,632 more cities, 47.9 µg/m³ and below

Not counted on this day, too few days measured: Manama since 17 Jul 2023, Rouyn-Noranda since 14 Jul 2023, Kigali since 10 Jul 2023 and 3 more cities. Days missing from the source archive fall in this window, so fewer countries are counted.

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.