SmogRank / World / France / Hauts-de-France / December 2025

Most unhealthy days in Hauts-de-France, France, December 2025

13 cities in Hauts-de-France, France ranked by their share of unhealthy days over the 31 days. The most unhealthy days: Béthune, France, 1 of 28 measured days. 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.

← Béthune 4% 3%0
Every city in Hauts-de-France, France ranked for December 2025, 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. 1Béthune
    1 of 28
  2. 2Douai
    0 of 23
  3. 3Amiens
    0 of 28
  4. 4Beauvais
    0 of 28
  5. 5Lille
    0 of 29
  6. 6Dunkirk
    0 of 29
  7. 7Creil
    0 of 28
  8. 8Valenciennes
    0 of 29
  9. 8Denain
    0 of 29
  10. 10Roubaix
    0 of 29
  11. 10Calais
    0 of 29
  12. 12Saint-Quentin
    0 of 28
  13. 12Boulogne-sur-Mer
    0 of 29
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

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SmogRank, most polluted cities in Hauts-de-France, France, by unhealthy days, PM2.5, December 2025, smogrank.com/fr/region/hauts-de-france/history/2025-12?by=days (accessed 7 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.