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 7 Jun 2025: Flin Flon 180.5 µg/m³, Nacimiento 95.3 µg/m³ and San Carlos 90.6 µg/m³.
- 1Flin FlonCanada180.5
- 2NacimientoChile95.3
- 3San CarlosChile90.6
- 4CoyhaiqueChile90.2
- 5HualpénChile88.9
- 6Santa Anita - Los FicusPeru87.0
- 7LinaresChile86.2
- 8Santa MaríaPeru82.4
- 9LajaChile80.8
- 10ChillánChile80.0
- 11CuricóChile76.8
- 12TemucoChile73.8
- 13CauquenesChile73.2
- 14SantiagoChile71.4
- 15RengoChile71.4
- 16VillarricaChile71.1
- 17Los ÁngelesChile71.1
- 18OsornoChile70.1
- 19HualquiChile70.1
- 20TalaganteChile69.7
+ 2,957 more cities, 68.9 µg/m³ and below
Not counted on this day, too few days measured: Bathinda since 1 Jun 2025, Siltara since 1 Jun 2025, Dispur since 28 May 2025 and 5 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 and Turkey, which publish only on their own websites; we are building the readers for them. Most cities there are missing from this board, not clean. Why.