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 30 days to28 Apr 2023 That day's board

The worst cities for PM2.5 over the 30 days to 28 Apr 2023: Dhaka 108.0 µg/m³, Kathmandu 82.5 µg/m³ and Bamako 70.7 µg/m³.

  1. 1DhakaBangladesh108.0
  2. 2KathmanduNepal82.5
  3. 3BamakoMali70.7
  4. 4BeijingChina63.4
  5. 5LahorePakistan62.9
  6. 6DelhiIndia62.5
  7. 7TlaquepaqueMexico61.0
  8. 8Bang Khun ThianThailand59.5
  9. 9ShenyangChina54.2
  10. 10CoyhaiqueChile54.0
  11. 11HyderabadIndia49.7
  12. 12HanoiVietnam49.7
  13. 13DushanbeTajikistan49.3
  14. 14San Mateo AtencoMexico46.3
  15. 15KhartoumSudan44.6
  16. 16YangonMyanmar43.8
  17. 17OsornoChile41.0
  18. 18BaghdadIraq40.4
  19. 19PeshawarPakistan40.1
  20. 20Puerto VarasChile39.8

+ 1,643 more cities, 38.7 µg/m³ and below

Not counted on this day, too few days measured: Sukhothai since 26 Apr 2023, Ratchaburi since 26 Apr 2023, Mae Sai since 26 Apr 2023 and 49 more cities. Days missing from the source archive fall in this window, so fewer countries are counted.

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.