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 to27 May 2024 That day's board

The worst cities for PM2.5 over the 7 days to 27 May 2024: Coyhaique 180.1 µg/m³, N'Djamena 136.2 µg/m³ and Santa María 127.4 µg/m³.

  1. 1CoyhaiqueChile180.1
  2. 2N'DjamenaChad136.2
  3. 3Santa MaríaPeru127.4
  4. 4OsornoChile126.5
  5. 5NacimientoChile117.7
  6. 6San CarlosChile101.5
  7. 7CuranilahueChile96.5
  8. 8HualpénChile94.0
  9. 9LajaChile90.9
  10. 10Puerto VarasChile90.2
  11. 11La UniónChile83.0
  12. 12DhakaBangladesh81.2
  13. 13Los ÁngelesChile76.9
  14. 14ChillánChile76.5
  15. 15LahorePakistan73.5
  16. 16Santa Anita - Los FicusPeru70.0
  17. 17ValdiviaChile69.2
  18. 18TemucoChile67.6
  19. 19CoronelChile67.2
  20. 20DelhiIndia65.9

+ 2,706 more cities, 65.5 µg/m³ and below

Not counted on this day, too few days measured: Cataño since 24 May 2024, Rengo since 23 May 2024, Jakarta since 21 May 2024 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.