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 18 Aug 2025: Coyhaique 109.5 µg/m³, Flin Flon 88.5 µg/m³ and Sri Ganganagar 81.4 µg/m³.
- 1CoyhaiqueChile109.5
- 2Flin FlonCanada88.5
- 3Sri GanganagarIndia81.4
- 4KigaliRwanda75.2
- 5NacimientoChile67.5
- 6OsornoChile66.6
- 7Puerto VarasChile58.8
- 8LinaresChile58.3
- 9GummidipundiIndia56.0
- 10CuricóChile56.0
- 11NagapattinamIndia54.9
- 12LajaChile54.6
- 13VillarricaChile54.1
- 14GujranwalaPakistan52.6
- 15ManamaBahrain51.4
- 16JhānsiIndia51.2
- 17FaisalabadPakistan50.9
- 18San CarlosChile50.7
- 19RengoChile50.7
- 20Santa MaríaPeru50.6
+ 3,065 more cities, the next at 49.0 µg/m³
Not counted on this day, too few days measured: Dhaulpur since 16 Aug 2025, Cholula since 26 Jul 2025 and Dispur since 19 Jul 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, 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.