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 to3 May 2026 That day's board

The worst cities for PM2.5 over the 30 days to 3 May 2026: Chiang Khong 111.3 µg/m³, Ban Houakhoua 111.3 µg/m³ and Loni 106.0 µg/m³.

  1. 1Chiang KhongThailand111.3
  2. 2Ban HouakhouaLaos111.3
  3. 3LoniIndia106.0
  4. 4GurugramIndia104.7
  5. 5Mae SaiThailand92.6
  6. 6Bueng KanThailand92.6
  7. 7PakxanLaos92.6
  8. 8NanThailand90.7
  9. 9Charkhi DādriIndia89.5
  10. 10PhayaoThailand88.6
  11. 11VientianeLaos86.5
  12. 12NarelaIndia83.6
  13. 13BawānaIndia80.4
  14. 14SingrauliIndia79.8
  15. 15Chiang RaiThailand79.5
  16. 16NarnaulIndia79.2
  17. 17JīndIndia76.9
  18. 18MānesarIndia76.1
  19. 19DādriIndia73.9
  20. 20LampangThailand73.0

+ 3,062 more cities, 72.7 µg/m³ and below

Not counted on this day, too few days measured: Hāpur since 3 May 2026, Siddharthanagar since 23 Apr 2026, Bishkek since 13 Apr 2026 and 3 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.