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 7 days to25 Dec 2023 That day's board

The worst cities for PM2.5 over the 7 days to 25 Dec 2023: Lahore 343.6 µg/m³, Delhi 242.3 µg/m³ and Dhaka 191.4 µg/m³.

  1. 1LahorePakistan343.6
  2. 2DelhiIndia242.3
  3. 3DhakaBangladesh191.4
  4. 4Ulan BatorMongolia186.9
  5. 5KolkataIndia179.1
  6. 6PeshawarPakistan149.3
  7. 7SalorUzbekistan133.4
  8. 8IslamabadPakistan131.0
  9. 9N'DjamenaChad128.5
  10. 10HyderabadIndia123.8
  11. 11Banja LukaBosnia and Herzegovina118.0
  12. 12SarajevoBosnia and Herzegovina116.4
  13. 13AbujaNigeria104.6
  14. 14NišSerbia92.9
  15. 15DushanbeTajikistan92.5
  16. 16LagosNigeria91.9
  17. 17TetovoNorth Macedonia91.4
  18. 18MumbaiIndia88.7
  19. 19SkopjeNorth Macedonia83.5
  20. 20KarachiPakistan82.0

+ 2,192 more cities, 80.6 µg/m³ and below

Not counted on this day, too few days measured: Cairo since 24 Dec 2023, Manama since 12 Dec 2023, Tha Bo since 30 Nov 2023 and 2 more cities.

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.