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.

The 7 days to28 Jul 2023 That day's board

The worst cities for PM2.5 over the 7 days to 28 Jul 2023: Coyhaique 115.8 µg/m³, Osorno 74.6 µg/m³ and Nacimiento 73.0 µg/m³.

  1. 1CoyhaiqueChile115.8
  2. 2OsornoChile74.6
  3. 3NacimientoChile73.0
  4. 4Puerto VarasChile66.5
  5. 5CuranilahueChile62.1
  6. 6DushanbeTajikistan59.1
  7. 7LinaresChile56.8
  8. 8TalcahuanoChile52.7
  9. 9Puerto AysénChile52.7
  10. 10CoronelChile50.0
  11. 11La UniónChile48.1
  12. 12RancaguaChile48.0
  13. 13San CarlosChile47.2
  14. 14Puerto MonttChile46.8
  15. 15TemucoChile46.5
  16. 16SantiagoChile46.4
  17. 17RengoChile45.7
  18. 18Ash ShīḩānīyahQatar45.5
  19. 19MoreliaMexico45.5
  20. 20ValdiviaChile44.6

+ 1,565 more cities, 44.4 µg/m³ and below

Not counted on this day, too few days measured: Ceglie Messapica since 28 Jul 2023, Laja since 27 Jul 2023, Hualpén since 26 Jul 2023 and 7 more cities.

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.