SmogRank / World / Europe / Switzerland / Basel-City
Most polluted cities in Basel-City, Switzerland
1 measured city, this year; 1 above the WHO annual guideline. The most unhealthy days: Basel, Switzerland, 1 of 268 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.
Now: cities by their PM2.5 over the last 24 hours; fires, smoke and ash from Oct 8, the newest day mapped.
- 1Basel 1 of 268
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
Estimated: cities without a monitor
Basel-City 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.
| City | 7-day estimate |
|---|---|
| Riehen | ≈ 10 µg/m³ |
Bad-air episodes in Basel-City
- Europe, 1 to 12 March 202612 days532 cities109 µg/m³peak, Radomsko
- Europe, January and February 202612 January to 12 February 2026, 32 days625 cities252 µg/m³peak, Travnik
- Europe, December 2025 to January 202625 December 2025 to 2 January 2026, 9 days189 cities110 µg/m³peak, Kempten (Allgäu)
- Germany, Poland and 25 more countries, March 20253 to 13 March 2025, 11 days553 cities152 µg/m³peak, Negotin
- Europe, 14 February to 1 March 202516 days619 cities178 µg/m³peak, Krotoszyn
- Europe, 1 to 14 February 202514 days628 cities179 µg/m³peak, Banja Luka
Times when many cities around here had PM2.5 at twice their usual or more on the same days.
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SmogRank, most polluted cities in Basel-City, Switzerland, by unhealthy days, PM2.5, this year to 10 Oct 2026, 04:00 UTC, smogrank.com/ch/region/basel-city?w=year&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.
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Updated 2026-10-10 04:07 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).