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 3 Jun 2024: N'Djamena 115.6 µg/m³, Coyhaique 115.1 µg/m³ and Osorno 112.0 µg/m³.
- 1N'DjamenaChad115.6
- 2CoyhaiqueChile115.1
- 3OsornoChile112.0
- 4Santa MaríaPeru110.8
- 5NacimientoChile82.8
- 6HualpénChile78.4
- 7Puerto VarasChile78.0
- 8CuricóChile74.1
- 9RancaguaChile72.7
- 10La UniónChile72.5
- 11TalaganteChile68.2
- 12LajaChile67.1
- 13RengoChile66.6
- 14SantiagoChile64.4
- 15San CarlosChile63.2
- 16CuranilahueChile61.4
- 17Santa Anita - Los FicusPeru59.8
- 18DelhiIndia59.3
- 19CoronelChile59.3
- 20Puerto MonttChile58.8
+ 2,637 more cities, 58.6 µg/m³ and below
Not counted on this day, too few days measured: Belmopan since 3 Jun 2024, Lahore since 1 Jun 2024, Cataño since 24 May 2024 and Tlaquepaque since 17 May 2024.
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.