SmogRank / Poland / Warmia-Masuria / Olsztyn
Olsztyn, month by month
Olsztyn has a measured daily mean on 1,110 days since 1 January 2023. Its worst month was January 2026, at 89 US AQI (29.7 µg/m³), 180th of 2,617 cities on that month's world ranking. Its cleanest was July 2026, at 27 US AQI (4.8 µg/m³). 2025 averaged 58 US AQI (12.8 µg/m³), against 61 US AQI (14.2 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
11 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 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 | 14 of 31 days measured; a month needs 22. The others: 17 with under 18 hours of readings or readings that failed our checks. |
| Jul 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. |
| 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 | 17 of 31 days measured; a month needs 22. The others: 14 with under 18 hours of readings or readings that failed our checks. |
| Apr 2023 | 19 of 30 days measured; a month needs 21. The others: 11 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.
Olsztyn's worst months
| Month | US AQI | World rank | Episode |
|---|---|---|---|
| January 2026 | 8929.7 µg/m³ | 180thof 2,617 | Europe, January and February 2026 |
| February 2025 | 8326.5 µg/m³ | 257thof 2,633 | Europe, 14 February to 1 March 2025 Europe, 1 to 14 February 2025 |
| March 2024 | 7522.0 µg/m³ | 124thof 1,698 | Europe, March and April 2024 Poland, 20 to 21 March 2024and 2 more |
| March 2025 | 7421.6 µg/m³ | 501stof 2,862 | Europe, March 2025 Germany, Poland and 25 more countries, March 2025and 1 more |
| February 2026 | 7321.0 µg/m³ | 517thof 2,866 | Europe, January and February 2026 |
| January 2024 | 6918.6 µg/m³ | 312thof 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.
Olsztyn's worst days
| Day | US AQI | Episode |
|---|---|---|
| 21 Jan 2026 | 17995.6 µg/m³ | Europe, January and February 2026 |
| 20 Jan 2026 | 16270.7 µg/m³ | Europe, January and February 2026 |
| 13 Jan 2026 | 15865.0 µg/m³ | Europe, January and February 2026 |
| 22 Jan 2026 | 15662.8 µg/m³ | Europe, January and February 2026 |
| 24 Feb 2025 | 15256.5 µg/m³ | Europe, 14 February to 1 March 2025 |
| 27 Feb 2025 | 15055.2 µg/m³ | Europe, 14 February to 1 March 2025 |
| 14 Jan 2026 | 14553.2 µg/m³ | Europe, January and February 2026 |
| 11 Mar 2025 | 13950.9 µg/m³ | Germany, Poland and 25 more countries, March 2025 |
| 26 Feb 2025 | 13850.6 µg/m³ | Europe, 14 February to 1 March 2025 |
| 12 Mar 2025 | 13850.5 µg/m³ | Germany, Poland and 25 more countries, 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, Olsztyn, Poland, 1 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/olsztyn/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.
Olsztyn 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).