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.
The worst cities for PM2.5 over the 7 days to 30 Jun 2023: Rouyn-Noranda 147.1 µg/m³, Coyhaique 138.6 µg/m³ and North Bay 104.4 µg/m³.
- 1Rouyn-NorandaCanada147.1
- 2CoyhaiqueChile138.6
- 3North BayCanada104.4
- 4SaguenayCanada101.4
- 5Greater SudburyCanada86.1
- 6HudsonvilleUnited States85.3
- 7JenisonUnited States85.3
- 8GreendaleUnited States81.8
- 9South MilwaukeeUnited States81.8
- 10DushanbeTajikistan79.9
- 11WaukeshaUnited States77.4
- 12Tha BoThailand77.0
- 13MadisonUnited States76.4
- 14RockfordUnited States73.8
- 15MilwaukeeUnited States72.7
- 16TecumsehUnited States71.4
- 17BarabooUnited States69.8
- 18SavoyUnited States68.4
- 19KalamazooUnited States68.4
- 20NapervilleUnited States67.8
+ 1,699 more cities, the next at 67.6 µg/m³
Not counted on this day, too few days measured: Guadalajara since 24 Jun 2023, Johannesburg since 14 Jun 2023, Bloemfontein since 12 Jun 2023 and 8 more cities.
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, 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.