SmogRank / World / Europe / Switzerland

Most polluted cities in Switzerland

9 measured cities, last 30 days; 0 above the WHO 24-hour guideline. The most unhealthy days: Giubiasco, Switzerland, 0 of 23 measured days.

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.

ValaisTicino: 2 measured citiesGrisonsSchaffhausenThurgau: 1 measured cityZurich: 2 measured citiesAargauBasel-City: 1 measured cityBasel-LandschaftSaint GallenSolothurnJuraGenevaVaud: 1 measured cityNeuchâtelBernLucerne: 1 measured cityZugUriSchwyz: 1 measured cityGlarusNidwaldenFribourgObwaldenAppenzell AusserrhodenAppenzell Innerrhoden#9 Küssnacht: 4.1 µg/m³#8 Sursee: 4.9 µg/m³#7 Basel: 5.8 µg/m³#6 Winterthur: 6.6 µg/m³#5 Payerne: 6.7 µg/m³#3 Zürich: 7.0 µg/m³#4 Lugano: 7.0 µg/m³#2 Kreuzlingen: 7.3 µg/m³#1 Giubiasco: 10.5 µg/m³
Each dot is a measured city, coloured by its PM2.5; tap a dot to open the city, or a region to zoom in.
← Giubiasco 0% 0.75%0
Every measured city in Switzerland, 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. 1GiubiascoTicino 0 of 23
  2. 2KreuzlingenThurgau 0 of 26
  3. 3ZürichZurich 0 of 24
  4. 3LuganoTicino 0 of 24
  5. 5PayerneVaud 0 of 23
  6. 6Winterthurlow-cost sensorsZurich 0 of 29
  7. 7BaselBasel-City 0 of 29
  8. 8SurseeLucerne 0 of 22
  9. 9KüssnachtSchwyz 0 of 23

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

Cleaner or dirtier than 2025

10 cities in Switzerland can be compared over 2026 so far (1 January to 8 October) with the same days of 2025: 4 got dirtier and 6 cleaner.

Biggest rises

Biggest falls

Every city in Switzerland, and past years

Estimated: cities without a monitor

Switzerland cities we can't measure, with model estimates for the last 7 days. Listed by population, not ranked: estimates aren't precise enough to rank. Model estimates from the Copernicus Atmosphere Monitoring Service (CAMS), adjusted to measured cities nearby where there are any. Adjusted, a single day lands within ×1.5 of what a monitor would read about two times in three; unadjusted, it can be off by half or double. Treat them as a guide, not a measurement.

City7-day estimateBand
Geneva≈ 9 µg/m³Moderate
Lausanne≈ 7 µg/m³Good
Luzern≈ 11 µg/m³Moderate
Sankt Gallen≈ 7 µg/m³Good
Biel/Bienne≈ 9 µg/m³Good
Thun≈ 7 µg/m³Good
Bellinzona≈ 13 µg/m³Moderate
Köniz≈ 8 µg/m³Good
Fribourg≈ 9 µg/m³Good
La Chaux-de-Fonds≈ 7 µg/m³Good
Schaffhausen≈ 8 µg/m³Good
Chur≈ 4 µg/m³Good
Rapperswil≈ 10 µg/m³Moderate
Uster≈ 10 µg/m³Moderate
Sitten≈ 5 µg/m³Good
Neuchâtel≈ 10 µg/m³Moderate
Emmen≈ 11 µg/m³Moderate
Zug≈ 11 µg/m³Moderate
Yverdon-les-Bains≈ 9 µg/m³Good
Vernier≈ 9 µg/m³Moderate
Montreux≈ 7 µg/m³Good
Frauenfeld≈ 8 µg/m³Good
Kriens≈ 11 µg/m³Moderate
Wetzikon≈ 10 µg/m³Moderate
Wil≈ 8 µg/m³Good
Bulle≈ 8 µg/m³Good
Horgen≈ 12 µg/m³Moderate
Opfikon≈ 7 µg/m³Good
Aarau≈ 13 µg/m³Moderate
Renens≈ 10 µg/m³Moderate
Dietikon≈ 8 µg/m³Good
Baar≈ 11 µg/m³Moderate
Bülach≈ 7 µg/m³Good
Riehen≈ 10 µg/m³Moderate
Vevey≈ 7 µg/m³Good
Dübendorf≈ 9 µg/m³Moderate
Meyrin≈ 9 µg/m³Good
Carouge≈ 12 µg/m³Moderate
Baden≈ 8 µg/m³Good
Reinach≈ 10 µg/m³Moderate

Bad-air episodes in Switzerland

Times when many cities here had PM2.5 at twice their usual or more on the same days.

All 31 episodes in Switzerland

Use this board

SmogRank, most polluted cities in Switzerland, by unhealthy days, PM2.5, last 30 days to 10 Oct 2026, 03:00 UTC, smogrank.com/ch?w=30d&by=days. Some readings from Uzhydromet (Uzbekistan's Hydrometeorological Service); Department of Environment, Nepal; Vietnam's government monitors; Aurassure; Umhverfisstofnun (Environment Agency of Iceland); Love My Air (City and County of Denver), no reuse terms published.

Download top 10 by average (PNG)

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.

Regions

Basel-City 1Lucerne 1Schwyz 1Thurgau 1Ticino 2Vaud 1Zurich 2

Measured cities in each region, last 30 days.

Updated 2026-10-10 03:07 UTC. Values are PM2.5 (fine particles), the median of each city's monitors, as the US AQI PM2.5 sub-index. Some readings: Uzhydromet (Uzbekistan's Hydrometeorological Service); Department of Environment, Nepal; Vietnam's government monitors; Aurassure; Umhverfisstofnun (Environment Agency of Iceland); Love My Air (City and County of Denver), no reuse terms published (why we use them).