SmogRank / Germany / Hesse / Zierenberg
Zierenberg, month by month
Zierenberg has a measured daily mean on 859 days since 5 December 2023. Its worst month was February 2025, at 69 US AQI (19.0 µg/m³), 637th of 2,633 cities on that month's world ranking. Its cleanest was October 2025, at 22 US AQI (4.0 µg/m³). 2025 averaged 39 US AQI (7.0 µg/m³), against 34 US AQI (6.2 µg/m³) in 2024.
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
6 months
| Month | Why |
|---|---|
| Jun 2026 | 16 of 30 days measured; a month needs 21. The others: 7 with no readings from the monitor, 7 with readings for part of the day (a day needs 18 hours). |
| Jun 2025 | 20 of 30 days measured; a month needs 21. The others: 10 with readings for part of the day (a day needs 18 hours). |
| Oct 2024 | 15 of 31 days measured; a month needs 22. The others: 16 with readings for part of the day (a day needs 18 hours). |
| Sep 2024 | No day measured. The others: 30 with readings for part of the day (a day needs 18 hours). |
| Aug 2024 | 15 of 31 days measured; a month needs 22. The others: 1 with no readings from the monitor, 15 with readings for part of the day (a day needs 18 hours). |
| Mar 2024 | 15 of 31 days measured; a month needs 22. The others: 10 with no readings from the monitor, 6 with readings for part of the day (a day needs 18 hours). |
A day counts once 18 hours of it are measured; a month needs 70% of its days.
Zierenberg's worst months
| Month | US AQI | World rank | Episode |
|---|---|---|---|
| February 2025 | 6919.0 µg/m³ | 637thof 2,633 | Europe, 1 to 14 February 2025 |
| March 2025 | 6114.3 µg/m³ | 1,008thof 2,862 | Europe, March 2025 Germany, Poland and 25 more countries, March 2025 |
| January 2026 | 5813.0 µg/m³ | 874thof 2,617 | Europe, January and February 2026 |
| March 2026 | 5410.9 µg/m³ | 1,446thof 2,971 | – |
| February 2026 | 519.2 µg/m³ | 1,620thof 2,866 | Europe, January and February 2026 |
| January 2024 | 397.1 µg/m³ | 1,490thof 2,385 | Europe, 8 to 27 January 2024 |
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.
Zierenberg's worst days
| Day | US AQI | Episode |
|---|---|---|
| 24 Jan 2026 | 14754.3 µg/m³ | Europe, January and February 2026 |
| 13 Feb 2025 | 13348.4 µg/m³ | Europe, 1 to 14 February 2025 |
| 10 Feb 2025 | 12946.9 µg/m³ | Europe, 1 to 14 February 2025 |
| 25 Jan 2026 | 11240.0 µg/m³ | Europe, January and February 2026 |
| 9 Feb 2025 | 11239.8 µg/m³ | Europe, 1 to 14 February 2025 |
| 11 Mar 2025 | 10938.7 µg/m³ | Germany, Poland and 25 more countries, March 2025 |
| 25 Mar 2025 | 10336.4 µg/m³ | Europe, March 2025 |
| 10 Mar 2025 | 9934.7 µg/m³ | Germany, Poland and 25 more countries, March 2025 |
| 23 Jan 2026 | 9231.2 µg/m³ | Europe, January and February 2026 |
| 9 Mar 2025 | 9130.6 µg/m³ | Germany, Poland and 25 more countries, March 2025 |
Daily means, the highest since 5 Dec 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, Zierenberg, Germany, 5 Dec 2023 – 12 Oct 2026. Monitor data from EEA, via OpenAQ and from the publisher directly; sources listed at smogrank.com/sources. smogrank.com/de/zierenberg/history (accessed 13 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.
Zierenberg now: the last 24 hours, its ranks today and the last 12 months day by day.
Updated 2026-10-13 01:07 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).