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 to25 May 2024 That day's board

The worst cities for PM2.5 over the 30 days to 25 May 2024: N'Djamena 175.6 µg/m³, Coyhaique 115.7 µg/m³ and Santa María 100.5 µg/m³.

  1. 1N'DjamenaChad175.6
  2. 2CoyhaiqueChile115.7
  3. 3Santa MaríaPeru100.5
  4. 4NacimientoChile93.3
  5. 5LahorePakistan86.5
  6. 6DelhiIndia82.3
  7. 7OsornoChile80.1
  8. 8HualpénChile77.6
  9. 9Chiang KhongThailand77.2
  10. 10Ban HouakhouaLaos77.2
  11. 11DhakaBangladesh70.2
  12. 12San CarlosChile70.1
  13. 13Puerto VarasChile69.9
  14. 14KathmanduNepal67.5
  15. 15CuranilahueChile66.0
  16. 16ChillánChile63.5
  17. 17LajaChile62.4
  18. 18La UniónChile59.7
  19. 19VillarricaChile59.2
  20. 20CoronelChile56.4

+ 2,818 more cities, the next at 54.7 µg/m³

Not counted on this day, too few days measured: Tlaquepaque since 23 May 2024.

30 days7 days
GoodModerateUnhealthy for sensitive 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, Turkey and Iran, which publish only on their own websites. We are building the reader for China's network. The networks of Turkey and Iran don't answer requests from outside their countries, so we can't read them. Most cities there are missing from this board, not clean. Why.