SmogRank / History / City race

Cities in United States, 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 to6 Mar 2026 That day's board

The worst cities in United States for PM2.5 over the 30 days to 6 Mar 2026: New Holland 18.7 µg/m³, Redford 18.5 µg/m³ and Wheaton 18.3 µg/m³.

  1. 1New HollandPennsylvania18.7
  2. 2RedfordMichigan18.5
  3. 3WheatonIllinois18.3
  4. 4YorkPennsylvania18.0
  5. 5TulareCalifornia17.6
  6. 6CamdenNew Jersey17.1
  7. 7LancasterPennsylvania16.4
  8. 8DelanoCalifornia16.3
  9. 9PortsmouthOhio15.9
  10. 10WheelersburgOhio15.9
  11. 11PalmyraNew Jersey15.9
  12. 12LaredoTexas15.5
  13. 13HersheyPennsylvania15.5
  14. 14AbingtonPennsylvania15.2
  15. 15Elmwood ParkIllinois15.1
  16. 16SkokieIllinois14.9
  17. 17Evergreen ParkIllinois14.8
  18. 18Ann ArborMichigan14.8
  19. 19ColumbusGeorgia14.7
  20. 20HarrisburgPennsylvania14.7

+ 850 more cities, 14.6 µg/m³ and below

Not counted on this day, too few days measured: Park Ridge since 3 Mar 2026, Rio Vista since 27 Feb 2026, Elk Grove since 1 Feb 2026 and San Mateo since 27 Jan 2026.

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.