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.

CountriesCities
The 30 days to14 Sep 2025 That day's board

The worst cities in United Kingdom for PM2.5 over the 30 days to 14 Sep 2025: Northampton 7.2 µg/m³, Speke 7.0 µg/m³ and London 6.7 µg/m³.

  1. 1NorthamptonEngland7.2
  2. 2SpekeEngland7.0
  3. 3LondonEngland6.7
  4. 4LeedsEngland6.7
  5. 5PlymouthEngland6.5
  6. 6ChepstowWales6.2
  7. 7ManchesterEngland6.0
  8. 8CardiffWales5.9
  9. 9HayesEngland5.8
  10. 10Newcastle upon TyneEngland5.7
  11. 11YorkEngland5.6
  12. 12PrestonEngland5.6
  13. 13DartfordEngland5.6
  14. 14SouthamptonEngland5.5
  15. 15DoncasterEngland5.5
  16. 16BirminghamEngland5.4
  17. 17BelfastNorthern Ireland5.4
  18. 18SheffieldEngland5.3
  19. 19Kingston upon HullEngland5.2
  20. 20IrlamEngland5.2

+ 45 more cities, the next at 5.2 µg/m³

Not counted on this day, too few days measured: Norwich since 13 Sep 2025, Nottingham since 4 Sep 2025 and Wigan since 28 Aug 2025.

30 days7 days
GoodModerateSensitive groupsUnhealthyVery unhealthyHazardousWHO 24-hour guideline, 15 µg/m³Fades where it stood: not counted that 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 reader for China's network. Turkey's network doesn't answer requests from outside the country, so we can't read it. Most cities there are missing from this board, not clean. Why.