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.
The worst cities in United States for PM2.5 over the 30 days to 16 Feb 2025: Socorro 17.6 µg/m³, Nogales 17.2 µg/m³ and Imperial Beach 16.7 µg/m³.
- 1SocorroTexas17.6
- 2NogalesArizona17.2
- 3Imperial BeachCalifornia16.7
- 4HanfordCalifornia16.5
- 5FresnoCalifornia16.0
- 6BadgerAlaska16.0
- 7VisaliaCalifornia14.8
- 8HelenaMontana14.6
- 9Helena Valley West CentralMontana14.6
- 10Jurupa ValleyCalifornia14.4
- 11ChicoCalifornia14.3
- 12BakersfieldCalifornia14.1
- 13CorcoranCalifornia14.1
- 14PhoenixArizona14.0
- 15Cottage GroveOregon14.0
- 16LewistonIdaho13.7
- 17AugustaGeorgia13.3
- 18Grants PassOregon13.3
- 19MedfordOregon13.2
- 20ParklandWashington13.1
+ 801 more cities, the next at 12.9 µg/m³
Not counted on this day, too few days measured: Florin since 26 Jan 2025, Columbia since 19 Jan 2025 and Oconomowoc since 19 Jan 2025.
Cities counted each 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 reader for China's network. Turkey's network doesn't answer requests from outside the country, so we can't read it. Most cities there are missing from this board, not clean. Why.