SmogRank / World / Germany / North Rhine-Westphalia / May 2026

Most polluted cities in North Rhine-Westphalia, Germany, May 2026

35 cities in North Rhine-Westphalia, Germany ranked by their average PM2.5 over the 31 days. Worst: Unna at 9.7 µg/m³, #829 of 2,852 cities in the world. Cleanest: Olpe at 3.8. A city needs measurements on 70% of the days to be ranked.

Ranked by unhealthy days: the share of each city's measured days with a daily mean over 35.4 µg/m³ (US AQI 101+), Unhealthy for Sensitive Groups or worse on the US EPA's scale. Ties go to the higher average.

← Unna 0% 0.75%0
Every city in North Rhine-Westphalia, Germany ranked for May 2026, one column each, ranked by unhealthy days: height is the share of its measured days that were unhealthy, colour its average. Point at it to read a city; tap to open it.
  1. 1Unna
    0%
  2. 2Gelsenkirchen
    0%
  3. 3Dortmund
    0%
  4. 4Münster
    0%
  5. 4Duisburg
    0%
  6. 4Bottrop
    0%
  7. 7Oberhausen
    0%
  8. 7Krefeld
    0%
  9. 7Hagen
    0%
  10. 7Essen
    0%
  11. 11Düsseldorf
    0%
  12. 12Jüchen
    0%
  13. 12Datteln
    0%
  14. 14Titz
    0%
  15. 15Warstein
    0%
  16. 16Wuppertal
    0%
  17. 16Mönchengladbach
    0%
  18. 16Aachen
    0%
  19. 19Wesel
    0%
  20. 19Köln
    0%
  21. 19Borken
    0%
  22. 22Niederzier
    0%
  23. 23Schwerte
    0%
  24. 23Leverkusen
    0%
  25. 25Kaldenkirchen
    0%
  26. 25Bonn
    0%
  27. 27Sinnersdorf
    0%
  28. 27Ratingen
    0%
  29. 27Bielefeld
    0%
  30. 30Hattingen
    0%
  31. 31Soest
    0%
  32. 32Lüdenscheid
    0%
  33. 33Roetgen
    0%
  34. 34Netphen
    0%
  35. 35Olpelow-cost sensors
    0%

Low-cost sensors: consumer units, counted only in cities with no government-grade monitor; they read close to reference monitors on the whole, but 15 to 25% high in humid air. How we use them.

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, May 2026 · All cities in Germany, May 2026 · North Rhine-Westphalia now

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SmogRank, most polluted cities in North Rhine-Westphalia, Germany, PM2.5, May 2026, smogrank.com/de/region/north-rhine-westphalia/history/2026-05 (accessed 6 Oct 2026).

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You're welcome to reuse a single chart, image or figure with this citation and a link. Terms. Raw monitor readings in bulk are published by OpenAQ, under each provider's licence.