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 30 days to 29 Aug 2023: Morelia 102.2 µg/m³, Osorno 75.9 µg/m³ and Nacimiento 69.2 µg/m³.
- 1MoreliaMexico102.2
- 2OsornoChile75.9
- 3NacimientoChile69.2
- 4Puerto VarasChile68.6
- 5CoyhaiqueChile64.5
- 6ManamaBahrain61.0
- 7Ash ShīḩānīyahQatar58.7
- 8KamloopsCanada57.4
- 9DhakaBangladesh52.0
- 10La UniónChile50.0
- 11DushanbeTajikistan48.5
- 12MedfordUnited States48.5
- 13JakartaIndonesia48.0
- 14AshlandUnited States47.6
- 15San CarlosChile46.7
- 16TemucoChile46.6
- 17RedmondUnited States46.5
- 18Puerto MonttChile45.1
- 19KigaliRwanda44.7
- 20PeshawarPakistan44.7
+ 2,071 more cities, the next at 44.3 µg/m³
Not counted on this day, too few days measured: Laja since 31 Jul 2023, Hualpén since 30 Jul 2023 and Tlaquepaque since 3 Jul 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, 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.