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 7 days to29 Jun 2023 That day's board

The worst cities for PM2.5 over the 7 days to 29 Jun 2023: Rouyn-Noranda 150.3 µg/m³, Coyhaique 128.7 µg/m³ and Saguenay 104.8 µg/m³.

  1. 1Rouyn-NorandaCanada150.3
  2. 2CoyhaiqueChile128.7
  3. 3SaguenayCanada104.8
  4. 4North BayCanada100.4
  5. 5DushanbeTajikistan87.7
  6. 6Greater SudburyCanada82.7
  7. 7MadisonUnited States79.1
  8. 8WaukeshaUnited States78.0
  9. 9Tha BoThailand77.2
  10. 10GreendaleUnited States74.9
  11. 11South MilwaukeeUnited States74.9
  12. 12RockfordUnited States74.7
  13. 13BarabooUnited States73.6
  14. 14MilwaukeeUnited States72.6
  15. 15JolietUnited States68.5
  16. 16NapervilleUnited States68.3
  17. 17TecumsehUnited States67.8
  18. 18BloomingtonUnited States65.7
  19. 19KalamazooUnited States65.4
  20. 20AppletonUnited States64.7

+ 1,647 more cities, 63.6 µg/m³ and below

Not counted on this day, too few days measured: Guadalajara since 24 Jun 2023, Johannesburg since 14 Jun 2023, Bloemfontein since 12 Jun 2023 and 8 more cities.

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.