SmogRank / Poland / Mazovia / Legionowo
Legionowo, month by month
Legionowo has a measured daily mean on 1,035 days since 11 January 2023. Its worst month was January 2026, at 109 US AQI (38.9 µg/m³), 91st of 2,617 cities on that month's world ranking. Its cleanest was July 2026, at 38 US AQI (6.9 µg/m³). 2025 averaged 62 US AQI (15.2 µg/m³), against 64 US AQI (15.9 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
14 months
| Month | Why |
|---|---|
| Oct 2026 | 5 of 11 days measured; a month needs 8. The others: 2 with no readings from the monitor, 4 with readings for part of the day (a day needs 18 hours). |
| May 2026 | No day measured. The others: 31 with under 18 hours of readings or readings that failed our checks. |
| Apr 2026 | 13 of 30 days measured; a month needs 21. The others: 17 with under 18 hours of readings or readings that failed our checks. |
| Dec 2024 | 11 of 31 days measured; a month needs 22. The others: 20 with under 18 hours of readings or readings that failed our checks. |
| Dec 2023 | No day measured. The others: 31 with under 18 hours of readings or readings that failed our checks. |
| Nov 2023 | No day measured. The others: 30 with under 18 hours of readings or readings that failed our checks. |
| Oct 2023 | 3 of 31 days measured; a month needs 22. The others: 28 with under 18 hours of readings or readings that failed our checks. |
| Aug 2023 | 15 of 31 days measured; a month needs 22. The others: 16 with under 18 hours of readings or readings that failed our checks. |
| Jul 2023 | 14 of 31 days measured; a month needs 22. The others: 17 with under 18 hours of readings or readings that failed our checks. |
| Jun 2023 | 18 of 30 days measured; a month needs 21. The others: 12 with under 18 hours of readings or readings that failed our checks. |
| May 2023 | 12 of 31 days measured; a month needs 22. The others: 19 with under 18 hours of readings or readings that failed our checks. |
| Apr 2023 | 3 of 30 days measured; a month needs 21. The others: 27 with under 18 hours of readings or readings that failed our checks. |
| Mar 2023 | 20 of 31 days measured; a month needs 22. The others: 11 with under 18 hours of readings or readings that failed our checks. |
| Jan 2023 | 7 of 31 days measured; a month needs 22. The others: 14 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.
Legionowo's worst months
| Month | US AQI | World rank | Episode |
|---|---|---|---|
| January 2026 | 10938.9 µg/m³ | 91stof 2,617 | Europe, January and February 2026 Poland, January 2026 |
| February 2025 | 10135.6 µg/m³ | 145thof 2,633 | Europe, 14 February to 1 March 2025 Poland, February 2025 |
| March 2025 | 8426.7 µg/m³ | 381stof 2,862 | Europe, March 2025 Germany, Poland and 25 more countries, March 2025and 1 more |
| February 2026 | 8326.5 µg/m³ | 330thof 2,866 | Europe, January and February 2026 |
| March 2026 | 8225.5 µg/m³ | 415thof 2,971 | Europe, 18 to 25 March 2026 Europe, 1 to 12 March 2026 |
| March 2024 | 8024.8 µg/m³ | 82ndof 1,698 | Europe, March and April 2024 Europe, February and March 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.
Legionowo's worst days
| Day | US AQI | Episode |
|---|---|---|
| 20 Jan 2026 | 17285.8 µg/m³ | Europe, January and February 2026 |
| 19 Jan 2026 | 17183.5 µg/m³ | Europe, January and February 2026 |
| 21 Jan 2026 | 16372.8 µg/m³ | Europe, January and February 2026 |
| 24 Feb 2025 | 16271.7 µg/m³ | Europe, 14 February to 1 March 2025 |
| 6 Jan 2026 | 16068.8 µg/m³ | Poland, January 2026 |
| 22 Jan 2026 | 15966.2 µg/m³ | Europe, January and February 2026 |
| 9 Jan 2024 | 15865.4 µg/m³ | Europe, 8 to 27 January 2024 |
| 8 Mar 2024 | 15865.1 µg/m³ | Europe, February and March 2024 |
| 26 Feb 2025 | 15764.0 µg/m³ | Europe, 14 February to 1 March 2025 |
| 22 Jan 2025 | 15560.8 µg/m³ | Germany, France and 19 more countries, January 2025 |
Daily means, the highest since 11 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, Legionowo, Poland, 11 Jan 2023 – 11 Oct 2026. Monitor data from EEA, via OpenAQ and from the publisher directly; sources listed at smogrank.com/sources. smogrank.com/pl/legionowo/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.
Legionowo now: the last 24 hours, its ranks today and the last 12 months day by day.
Updated 2026-10-12 20:07 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).