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 28 May 2023: Miles City 18.9 µg/m³, Texarkana 17.2 µg/m³ and Havre 16.8 µg/m³.
- 1Miles CityMontana18.9
- 2TexarkanaTexas17.2
- 3HavreMontana16.8
- 4Port IsabelTexas16.2
- 5HobbsNew Mexico15.8
- 6West FargoNorth Dakota15.6
- 7BaytownTexas14.6
- 8HighlandsTexas14.6
- 9HernandoMississippi14.5
- 10Great FallsMontana14.5
- 11Rapid CitySouth Dakota14.5
- 12ClevelandMississippi14.4
- 13HelenaMontana14.4
- 14Helena Valley West CentralMontana14.4
- 15HoustonTexas14.3
- 16Lacy-LakeviewTexas14.0
- 17ParadiseCalifornia13.9
- 18Columbia FallsMontana13.9
- 19PierreSouth Dakota13.9
- 20BurnsvilleMinnesota13.8
+ 717 more cities, the next at 13.8 µg/m³
Not counted on this day, too few days measured: Los Angeles since 25 May 2023, Chalmette since 30 Mar 2023 and Lincoln Park since 30 Mar 2023.
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.