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 to19 Apr 2025 That day's board

The worst cities for PM2.5 over the 7 days to 19 Apr 2025: Delhi 65.3 µg/m³, Sunland Park 54.9 µg/m³ and Ubon Ratchathani 52.6 µg/m³.

  1. 1DelhiIndia65.3
  2. 2Sunland ParkUnited States54.9
  3. 3Ubon RatchathaniThailand52.6
  4. 4IslamabadPakistan52.0
  5. 5CoyhaiqueChile50.6
  6. 6GuangzhouChina50.5
  7. 7OsornoChile48.5
  8. 8VillarricaChile45.9
  9. 9HualpénChile44.6
  10. 10HualquiChile44.5
  11. 11Wan ChaiHong Kong44.4
  12. 12Tuen MunHong Kong43.8
  13. 13NacimientoChile43.6
  14. 14El PasoUnited States41.3
  15. 15FanlingHong Kong41.2
  16. 16AnthonyUnited States41.1
  17. 17YasothonThailand40.9
  18. 18CuernavacaMexico40.7
  19. 19Mong KokHong Kong40.3
  20. 20Victoria de DurangoMexico40.2

+ 2,934 more cities, 38.4 µg/m³ and below

Not counted on this day, too few days measured: Hanoi since 12 Apr 2025, Siliguri since 11 Apr 2025, Sawai Madhopur since 11 Apr 2025 and 54 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.