SmogRank / Slovakia / Trenčín Region / Trenčín
Trenčín, month by month
Trenčín has a measured daily mean on 1,012 days since 1 January 2023. Its worst month was February 2025, at 85 US AQI (27.3 µg/m³), 243rd of 2,633 cities on that month's world ranking. Its cleanest was September 2025, at 38 US AQI (6.8 µg/m³). 2025 averaged 57 US AQI (12.5 µg/m³), against 56 US AQI (12.0 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
14 months
| Month | Why |
|---|---|
| Aug 2026 | 20 of 31 days measured; a month needs 22. The others: 11 with under 18 hours of readings or readings that failed our checks. |
| Jul 2026 | No day measured. The others: 31 with under 18 hours of readings or readings that failed our checks. |
| Jun 2026 | 18 of 30 days measured; a month needs 21. The others: 12 with under 18 hours of readings or readings that failed our checks. |
| Mar 2026 | 18 of 31 days measured; a month needs 22. The others: 13 with under 18 hours of readings or readings that failed our checks. |
| Feb 2026 | No day measured. The others: 28 with under 18 hours of readings or readings that failed our checks. |
| Jan 2026 | No day measured. The others: 31 with under 18 hours of readings or readings that failed our checks. |
| Dec 2025 | 5 of 31 days measured; a month needs 22. The others: 26 with under 18 hours of readings or readings that failed our checks. |
| Oct 2025 | 19 of 31 days measured; a month needs 22. The others: 12 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 | 13 of 31 days measured; a month needs 22. The others: 18 with under 18 hours of readings or readings that failed our checks. |
| Apr 2024 | 18 of 30 days measured; a month needs 21. The others: 12 with under 18 hours of readings or readings that failed our checks. |
| Mar 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. |
| May 2023 | 18 of 31 days measured; a month needs 22. The others: 13 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.
Trenčín's worst months
| Month | US AQI | World rank | Episode |
|---|---|---|---|
| February 2025 | 8527.3 µg/m³ | 243rdof 2,633 | Europe, 14 February to 1 March 2025 Europe, 1 to 14 February 2025 |
| November 2024 | 7421.2 µg/m³ | 182ndof 2,624 | Southern Europe, November 2024 Europe, November 2024 |
| February 2023 | 7119.6 µg/m³ | 138thof 1,129 | Europe, 28 February to 4 March 2023 Europe, 6 to 25 February 2023 |
| March 2025 | 7019.5 µg/m³ | 603rdof 2,862 | Germany, Poland and 25 more countries, March 2025 Europe, 14 February to 1 March 2025 |
| December 2023 | 6918.7 µg/m³ | 185thof 2,247 | South-eastern Europe, 28 December 2023 to 1 January 2024 Eastern Europe, December 2023and 1 more |
| January 2024 | 6818.0 µg/m³ | 336thof 2,385 | Europe, 27 January to 2 February 2024 Europe, 8 to 27 January 2024and 1 more |
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.
Trenčín's worst days
| Day | US AQI | Episode |
|---|---|---|
| 11 Feb 2023 | 15864.9 µg/m³ | Europe, 6 to 25 February 2023 |
| 29 Dec 2024 | 15561.9 µg/m³ | Europe, 24 December 2024 to 3 January 2025 |
| 10 Feb 2023 | 15256.9 µg/m³ | Europe, 6 to 25 February 2023 |
| 16 Feb 2023 | 13047.3 µg/m³ | Europe, 6 to 25 February 2023 |
| 1 Feb 2024 | 13047.2 µg/m³ | Europe, 27 January to 2 February 2024 |
| 28 Dec 2024 | 12645.5 µg/m³ | Europe, 24 December 2024 to 3 January 2025 |
| 9 Feb 2023 | 12344.5 µg/m³ | Europe, 6 to 25 February 2023 |
| 5 Feb 2025 | 12143.8 µg/m³ | Europe, 1 to 14 February 2025 |
| 24 Feb 2025 | 12043.1 µg/m³ | Europe, 14 February to 1 March 2025 |
| 23 Jan 2024 | 11842.4 µg/m³ | Europe, 8 to 27 January 2024 |
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, Trenčín, Slovakia, 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/sk/trencin/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.
Trenčín now: the last 24 hours, its ranks today and the last 12 months day by day.
Updated 2026-10-12 21:07 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).