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 to27 Mar 2023 That day's board

The worst cities for PM2.5 over the 7 days to 27 Mar 2023: N'Djamena 99.0 µg/m³, Bamako 89.7 µg/m³ and Khartoum 65.7 µg/m³.

  1. 1N'DjamenaChad99.0
  2. 2BamakoMali89.7
  3. 3KhartoumSudan65.7
  4. 4DelhiIndia58.6
  5. 5LahorePakistan54.7
  6. 6TlaquepaqueMexico53.0
  7. 7CholulaMexico48.7
  8. 8PeshawarPakistan46.7
  9. 9AlexandriaEgypt45.9
  10. 10AbujaNigeria41.9
  11. 11San Francisco TlalcilalcalpanMexico41.5
  12. 12Santiaguito TlalcilalcalliMexico41.5
  13. 13BaghdadIraq40.4
  14. 14Ciudad Benito JuárezMexico39.2
  15. 15DushanbeTajikistan38.3
  16. 16KathmanduNepal35.3
  17. 17CelayaMexico33.8
  18. 18San Mateo AtencoMexico33.7
  19. 19IslamabadPakistan33.2
  20. 20San CarlosChile32.8

+ 1,635 more cities, 32.3 µg/m³ and below

Not counted on this day, too few days measured: Reykjavík since 27 Mar 2023, Kościan since 26 Mar 2023, Siedlce since 25 Mar 2023 and 41 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.