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 1 May 2023: Kathmandu 84.6 µg/m³, Bamako 75.5 µg/m³ and Dhaka 66.5 µg/m³.
- 1KathmanduNepal84.6
- 2BamakoMali75.5
- 3DhakaBangladesh66.5
- 4DelhiIndia62.8
- 5San CarlosChile57.0
- 6BelmopanBelize52.4
- 7ChillánChile52.3
- 8LinaresChile50.6
- 9LahorePakistan46.1
- 10CholulaMexico45.4
- 11LajaChile43.7
- 12CoyhaiqueChile42.6
- 13NacimientoChile41.6
- 14CuricóChile41.1
- 15RancaguaChile40.7
- 16ShanghaiChina40.5
- 17Puerto VarasChile40.5
- 18CelayaMexico39.9
- 19TalcaChile39.7
- 20San Mateo AtencoMexico38.6
+ 1,655 more cities, the next at 38.5 µg/m³
Not counted on this day, too few days measured: Kampala since 1 May 2023, Hyderabad since 1 May 2023, Quillota since 30 Apr 2023 and 58 more cities. Days missing from the source archive fall in this window, so fewer countries are counted.
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.