SmogRank / World / Japan / Hokkaido / December 2025

Most polluted cities in Hokkaido, Japan, December 2025

10 cities in Hokkaido, Japan ranked by their average PM2.5 over the 31 days. Worst: Kitami at 9.2 µg/m³, #1,515 of 2,960 cities in the world. Cleanest: Tomakomai at 4.4. 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.

← Kitami 0% 0.75%0
Every city in Hokkaido, Japan 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. 1Kitami
    0%
  2. 2Obihiro
    0%
  3. 3Chitose
    0%
  4. 4Muroran
    0%
  5. 5Asahikawa
    0%
  6. 6Hakodate
    0%
  7. 7Sapporo
    0%
  8. 8Kushiro
    0%
  9. 9Tōma
    0%
  10. 10Tomakomai
    0%
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, December 2025 · All cities in Japan, December 2025 · Hokkaido now

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SmogRank, most polluted cities in Hokkaido, Japan, PM2.5, December 2025, smogrank.com/jp/region/hokkaido/history/2025-12 (accessed 6 Oct 2026).

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