SmogRank / Countries / Switzerland / September 2025

Most polluted cities in Switzerland, September 2025

6 cities in Switzerland ranked by their average PM2.5 over the 30 days. Worst: Winterthur at 7.5 µg/m³, #1,085 of 2,439 cities in the world. Cleanest: Lugano at 4.2. A city needs measurements on 70% of the days to be ranked.

  1. 1Winterthurlow-cost sensorsZurich
    7.5
  2. 2BaselBasel-City
    5.4
  3. 3BernBern
    4.7
  4. 3BellinzonaTicino
    4.7
  5. 5ZürichZurich
    4.5
  6. 6LuganoTicino
    4.2
Good0–9.0
Moderate9.1–35.4
Sensitive groups35.5–55.4
Unhealthy55.5–125.4
Very unhealthy125.5–225.4
Hazardous225.5+

All cities in the world, September 2025 · Switzerland now