SmogRank / History / City race
Cities in United Kingdom, 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 in United Kingdom for PM2.5 over the 30 days to 25 Apr 2023: Cardiff 12.6 µg/m³, Cwmafan 10.4 µg/m³ and Briton Ferry 10.4 µg/m³.
- 1CardiffWales12.6
- 2CwmafanWales10.4
- 3Briton FerryWales10.4
- 4HooEngland10.0
- 5BrightonEngland10.0
- 6Canvey IslandEngland10.0
- 7NottinghamEngland9.9
- 8CanterburyEngland9.7
- 9PortsmouthEngland9.6
- 10Stoke-on-TrentEngland9.5
- 11NorwichEngland9.4
- 12ManchesterEngland9.3
- 13Kingston upon HullEngland9.3
- 14ChepstowWales9.3
- 15BirminghamEngland9.3
- 16BexleyEngland9.3
- 17LondonEngland9.1
- 18BarnstapleEngland9.1
- 19PlymouthEngland9.0
- 20Clacton-on-SeaEngland8.9
+ 28 more cities, 8.9 µg/m³ and below
Not counted on this day, too few days measured: Sheffield since 25 Apr 2023, Irlam since 25 Apr 2023, Sheringham since 24 Apr 2023 and Grays since 21 Apr 2023. 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 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.