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 30 days to20 Oct 2023 That day's board

The worst cities for PM2.5 over the 30 days to 20 Oct 2023: N'Djamena 79.4 µg/m³, Lahore 71.1 µg/m³ and Dhaka 69.1 µg/m³.

  1. 1N'DjamenaChad79.4
  2. 2LahorePakistan71.1
  3. 3DhakaBangladesh69.1
  4. 4PeshawarPakistan68.7
  5. 5DelhiIndia61.7
  6. 6KolkataIndia53.3
  7. 7HyderabadIndia49.1
  8. 8JakartaIndonesia48.9
  9. 9CairoEgypt48.5
  10. 10KarachiPakistan43.9
  11. 11Ash ShīḩānīyahQatar40.2
  12. 12HanoiVietnam39.0
  13. 13Şabāḩ as SālimKuwait38.2
  14. 14Puerto VarasChile37.8
  15. 15BamakoMali37.3
  16. 16CoyhaiqueChile35.9
  17. 17DushanbeTajikistan35.8
  18. 18KampalaUganda35.7
  19. 19MumbaiIndia35.5
  20. 20IslamabadPakistan34.5

+ 2,123 more cities, 34.0 µg/m³ and below

Not counted on this day, too few days measured: Xonacatlán since 14 Oct 2023, Kigali since 24 Sep 2023, Alexandria since 22 Sep 2023 and 2 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.