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 to31 Aug 2023 That day's board

The worst cities for PM2.5 over the 7 days to 31 Aug 2023: Grants Pass 123.5 µg/m³, Osorno 121.4 µg/m³ and Puerto Varas 111.1 µg/m³.

  1. 1Grants PassUnited States123.5
  2. 2OsornoChile121.4
  3. 3Puerto VarasChile111.1
  4. 4GreenUnited States103.8
  5. 5Fort McMurrayCanada95.1
  6. 6YrekaUnited States93.8
  7. 7MedfordUnited States92.2
  8. 8AshlandUnited States88.1
  9. 9TalentUnited States87.9
  10. 10DhakaBangladesh78.9
  11. 11NacimientoChile71.7
  12. 12Grande PrairieCanada65.6
  13. 13La UniónChile60.6
  14. 14KolkataIndia58.1
  15. 15BendUnited States57.0
  16. 16Fort St. JohnCanada53.6
  17. 17EdmontonCanada52.7
  18. 18CuranilahueChile51.9
  19. 19AlexandriaEgypt51.6
  20. 20Los ÁngelesChile50.9

+ 1,598 more cities, 50.2 µg/m³ and below

Not counted on this day, too few days measured: Manama since 28 Aug 2023, Jakarta since 28 Aug 2023, Ash Shīḩānīyah since 27 Aug 2023 and 3 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.