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 Nov 2023 That day's board

The worst cities for PM2.5 over the 7 days to 29 Nov 2023: Lahore 321.6 µg/m³, Delhi 213.7 µg/m³ and Kolkata 155.7 µg/m³.

  1. 1LahorePakistan321.6
  2. 2DelhiIndia213.7
  3. 3KolkataIndia155.7
  4. 4DhakaBangladesh146.7
  5. 5KarachiPakistan116.7
  6. 6IslamabadPakistan91.4
  7. 7TlaquepaqueMexico75.5
  8. 8CairoEgypt73.7
  9. 9SarajevoBosnia and Herzegovina63.1
  10. 10HyderabadIndia58.7
  11. 11MumbaiIndia56.2
  12. 12Samut SakhonThailand53.4
  13. 13Ulan BatorMongolia51.3
  14. 14GuangzhouChina48.2
  15. 15JakartaIndonesia48.1
  16. 16CapannoriItaly43.5
  17. 17KathmanduNepal43.4
  18. 18AbujaNigeria43.1
  19. 19DushanbeTajikistan42.0
  20. 20CastlegarCanada41.5

+ 2,272 more cities, 40.4 µg/m³ and below

Not counted on this day, too few days measured: Veracruz since 29 Nov 2023, N'Djamena since 26 Nov 2023, Peshawar since 25 Nov 2023 and 11 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.