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 to19 May 2023 That day's board

The worst cities for PM2.5 over the 30 days to 19 May 2023: Grande Prairie 76.5 µg/m³, Dhaka 69.2 µg/m³ and Lahore 66.5 µg/m³.

  1. 1Grande PrairieCanada76.5
  2. 2DhakaBangladesh69.2
  3. 3LahorePakistan66.5
  4. 4DelhiIndia65.6
  5. 5LinaresChile58.1
  6. 6KathmanduNepal55.0
  7. 7NacimientoChile54.4
  8. 8OsornoChile53.3
  9. 9San CarlosChile48.1
  10. 10CuricóChile47.7
  11. 11LajaChile47.2
  12. 12RancaguaChile46.2
  13. 13Puerto VarasChile45.9
  14. 14SantiagoChile45.5
  15. 15ChillánChile43.6
  16. 16Fort St. JohnCanada43.2
  17. 17HyderabadIndia43.0
  18. 18PeshawarPakistan42.3
  19. 19TalaganteChile42.0
  20. 20HualquiChile41.8

+ 1,553 more cities, 41.8 µg/m³ and below

Not counted on this day, too few days measured: Belmopan since 15 May 2023, Shenyang since 13 May 2023, Khartoum since 11 May 2023 and 60 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.