SmogRank / Countries / Switzerland / May 2026

Most polluted cities in Switzerland, May 2026

5 cities in Switzerland ranked by their average PM2.5 over the 31 days. Worst: Bellinzona at 6.8 µg/m³, #1,285 of 2,243 cities in the world. Cleanest: Winterthur at 5.0. A city needs measurements on 70% of the days to be ranked.

  1. 1BellinzonaTicino
    6.8
  2. 2ZürichZurich
    6.5
  3. 3BaselBasel-City
    6.0
  4. 4LuganoTicino
    5.4
  5. 5Winterthurlow-cost sensorsZurich
    5.0
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, May 2026 · Switzerland now