SmogRank / Switzerland / Zurich / Zürich
Zürich, month by month
Zürich has a measured daily mean on 1,024 days since 1 January 2023. Its worst month was February 2025, at 71 US AQI (19.7 µg/m³), 592nd of 2,633 cities on that month's world ranking. Its cleanest was November 2023, at 18 US AQI (3.2 µg/m³). 2025 averaged 51 US AQI (9.1 µg/m³), against 38 US AQI (6.9 µg/m³) in 2023.
Every month since 2023
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
Months without a mean, and why
11 months
| Month | Why |
|---|---|
| Jun 2026 | 15 of 30 days measured; a month needs 21. The others: 15 with under 18 hours of readings or readings that failed our checks. |
| Jun 2025 | 19 of 30 days measured; a month needs 21. The others: 11 with under 18 hours of readings or readings that failed our checks. |
| Oct 2024 | 14 of 31 days measured; a month needs 22. The others: 17 with under 18 hours of readings or readings that failed our checks. |
| Sep 2024 | No day measured. The others: 30 with under 18 hours of readings or readings that failed our checks. |
| Aug 2024 | 15 of 31 days measured; a month needs 22. The others: 16 with under 18 hours of readings or readings that failed our checks. |
| Jun 2024 | 5 of 30 days measured; a month needs 21. The others: 25 with under 18 hours of readings or readings that failed our checks. |
| Apr 2024 | No day measured. The others: 30 with under 18 hours of readings or readings that failed our checks. |
| Mar 2024 | 10 of 31 days measured; a month needs 22. The others: 21 with under 18 hours of readings or readings that failed our checks. |
| Mar 2023 | 11 of 31 days measured; a month needs 22. The others: 20 missing from OpenAQ's archive. |
| Feb 2023 | 2 of 28 days measured; a month needs 20. The others: 25 missing from OpenAQ's archive, 1 with under 18 hours of readings or readings that failed our checks. |
| Jan 2023 | 8 of 31 days measured; a month needs 22. The others: 7 missing from OpenAQ's archive, 16 with under 18 hours of readings or readings that failed our checks. |
A day counts once 18 hours of it are measured; a month needs 70% of its days.
Zürich's worst months
| Month | US AQI | World rank | Episode |
|---|---|---|---|
| February 2025 | 7119.7 µg/m³ | 592ndof 2,633 | Europe, 14 February to 1 March 2025 Europe, 1 to 14 February 2025 |
| January 2026 | 6114.3 µg/m³ | 793rdof 2,617 | Europe, December 2025 to January 2026 |
| March 2026 | 5913.2 µg/m³ | 1,037thof 2,971 | Europe, 1 to 12 March 2026 |
| January 2025 | 5511.3 µg/m³ | 804thof 2,474 | Germany, France and 19 more countries, January 2025 Europe, 24 December 2024 to 3 January 2025 |
| December 2025 | 5511.3 µg/m³ | 1,072ndof 3,006 | Europe, December 2025 to January 2026 |
| March 2025 | 5310.2 µg/m³ | 1,562ndof 2,862 | Europe, 14 February to 1 March 2025 |
Monthly means over the days measured; finished months only. World rank: its place on that month's world ranking of every city with enough days. Each month opens that ranking.
Zürich's worst days
| Day | US AQI | Episode |
|---|---|---|
| 1 Jan 2026 | 16169.4 µg/m³ | Europe, December 2025 to January 2026 |
| 1 Jan 2025 | 11842.4 µg/m³ | Europe, 24 December 2024 to 3 January 2025 |
| 1 May 2025 | 11842.3 µg/m³ | – |
| 8 Mar 2026 | 10637.6 µg/m³ | Europe, 1 to 12 March 2026 |
| 7 Mar 2026 | 9934.8 µg/m³ | Europe, 1 to 12 March 2026 |
| 11 Feb 2025 | 9532.9 µg/m³ | Europe, 1 to 14 February 2025 |
| 10 Feb 2025 | 9230.9 µg/m³ | Europe, 1 to 14 February 2025 |
| 9 Mar 2026 | 8929.3 µg/m³ | Europe, 1 to 12 March 2026 |
| 19 Jan 2025 | 8426.8 µg/m³ | Germany, France and 19 more countries, January 2025 |
| 19 Feb 2025 | 8426.8 µg/m³ | Europe, 14 February to 1 March 2025 |
Daily means, the highest since 1 Jan 2023; the WHO's daily guideline is 15 µg/m³. Each date opens that day's world ranking, and each episode the bad-air spell it was part of.
Use this history
SmogRank, PM2.5 monthly and daily means, Zürich, Switzerland, 1 Jan 2023 – 12 Oct 2026. Monitor data from EEA, via OpenAQ and from the publisher directly; sources listed at smogrank.com/sources. smogrank.com/ch/zuerich/history (accessed 12 Oct 2026).
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.
Zürich now: the last 24 hours, its ranks today and the last 12 months day by day.
Updated 2026-10-12 22:07 UTC. Values are PM2.5 (fine particles), the median of each city's monitors, as the US AQI PM2.5 sub-index. Some low-cost readings: Sensor.Community, ODbL (data and licence). Some readings: Uzhydromet (Uzbekistan's Hydrometeorological Service); Department of Environment, Nepal; Vietnam's government monitors; Aurassure; Umhverfisstofnun (Environment Agency of Iceland); RMCAB (Secretaría Distrital de Ambiente, Bogotá); Love My Air (City and County of Denver), no reuse terms published (why we use them).