SmogRank / World / United Kingdom / September 2025

Most polluted cities in United Kingdom, September 2025

54 cities in United Kingdom ranked by their average PM2.5 over the 30 days. Worst: Northampton at 7.5 µg/m³, #1,307 of 2,711 cities in the world. Cleanest: Derry at 2.2. A city needs measurements on 70% of the days to be ranked.

← Northampton 7.5 µg/m³ 20 µg/m³0
Every city in United Kingdom ranked for September 2025, one column each, worst on the left and cleanest on the right; height is PM2.5 in µg/m³. Point at it to read a city; tap to open it.
  1. 1NorthamptonEngland
    42
  2. 2LondonEngland
    39
  3. 3SpekeEngland
    36
  4. 4LeedsEngland
    34
  5. 5DartfordEngland
    34
  6. 6ScunthorpeEngland
    33
  7. 7PlymouthEngland
    33
  8. 8CardiffWales
    32
  9. 9HayesEngland
    32
  10. 10Kingston upon HullEngland
    31
  11. 10DoncasterEngland
    31
  12. 12SouthamptonEngland
    31
  13. 12Manchesterlow-cost sensorsEngland
    31
  14. 14LutonEngland
    30
  15. 15Newcastle upon TyneEngland
    29
  16. 16BrightonEngland
    29
  17. 17DerbyEngland
    28
  18. 17Birminghamlow-cost sensorsEngland
    28
  19. 17BexleyEngland
    28
  20. 17Canvey IslandEngland
    28
  21. 21WiganEngland
    28
  22. 21PortsmouthEngland
    28
  23. 21LeicesterEngland
    28
  24. 21BristolEngland
    28
  25. 25SeafordEngland
    27
  26. 26YorkEngland
    27
  27. 26SunderlandEngland
    27
  28. 26SheffieldEngland
    27
  29. 29Stoke-on-TrentEngland
    26
  30. 30PrestonEngland
    26
  31. 30NewportWales
    26
  32. 30Clacton-on-SeaEngland
    26
  33. 33Royal Leamington SpaEngland
    25
  34. 33BelfastNorthern Ireland
    25
  35. 35AndoverEngland
    24
  36. 36ReadingEngland
    23
  37. 36CannockEngland
    23
  38. 36BarnstapleEngland
    23
  39. 39LiverpoolEngland
    23
  40. 39IrlamEngland
    23
  41. 41ChesterfieldEngland
    22
  42. 42NewmarketEngland
    22
  43. 42BarnsleyEngland
    22
  44. 44GrangemouthScotland
    21
  45. 45OxfordEngland
    20
  46. 45MiddlesbroughEngland
    20
  47. 45GlasgowScotland
    20
  48. 45High PeakEngland
    20
  49. 49Westburylow-cost sensorsEngland
    18
  50. 49EdinburghScotland
    18
  51. 49Briton FerryWales
    18
  52. 52SaltashEngland
    16
  53. 53PenicuikScotland
    13
  54. 54DerryNorthern Ireland
    12
Good0–50
Moderate51–100
Sensitive groups101–150
Unhealthy151–200
Very unhealthy201–300
Hazardous301+

The US EPA's Air Quality Index for PM2.5 (2024 breakpoints). Show values as: µg/m³ · US AQI · India AQI · China AQI · European AQI · UK DAQI · Canada AQHI+. About the scales

All cities in the world, September 2025 · United Kingdom now

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SmogRank, most polluted cities in United Kingdom, PM2.5, September 2025, smogrank.com/gb/history/2025-09 (accessed 2 Oct 2026).

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