SmogRank / Romania / Cluj County / Cluj-Napoca
Cluj-Napoca, month by month
Cluj-Napoca has a measured daily mean on 1,186 days since 1 January 2023. Its worst month was January 2026, at 112 US AQI (39.8 µg/m³), 85th of 2,617 cities on that month's world ranking. Its cleanest was May 2025, at 38 US AQI (6.8 µg/m³). 2025 averaged 62 US AQI (15.0 µg/m³), against 67 US AQI (17.6 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
7 months
| Month | Why |
|---|---|
| Oct 2026 | 8 of 12 days measured; a month needs 9. The others: 3 with readings for part of the day (a day needs 18 hours), 1 with under 18 hours of readings or readings that failed our checks. |
| Nov 2025 | 18 of 30 days measured; a month needs 21. The others: 12 with under 18 hours of readings or readings that failed our checks. |
| Oct 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. |
| 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. |
| Mar 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 2023 | 16 of 30 days measured; a month needs 21. 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.
Cluj-Napoca's worst months
| Month | US AQI | World rank | Episode |
|---|---|---|---|
| January 2026 | 11239.8 µg/m³ | 85thof 2,617 | Europe, January and February 2026 |
| January 2025 | 9030.3 µg/m³ | 90thof 2,474 | Germany, France and 19 more countries, January 2025 Eastern Europe, January 2025and 1 more |
| November 2024 | 8627.8 µg/m³ | 78thof 2,624 | Eastern Europe, 25 to 29 November 2024 Southern Europe, November 2024and 2 more |
| February 2025 | 8627.8 µg/m³ | 239thof 2,633 | Europe, 14 February to 1 March 2025 Europe, 1 to 14 February 2025 |
| January 2024 | 8527.3 µg/m³ | 137thof 2,385 | Europe, 27 January to 2 February 2024 Europe, 8 to 27 January 2024and 1 more |
| February 2024 | 8527.1 µg/m³ | 124thof 2,486 | Europe, February and March 2024 Europe, 27 January to 2 February 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.
Cluj-Napoca's worst days
| Day | US AQI | Episode |
|---|---|---|
| 22 Jan 2026 | 187107.0 µg/m³ | Europe, January and February 2026 |
| 21 Jan 2026 | 183101.0 µg/m³ | Europe, January and February 2026 |
| 18 Dec 2025 | 16879.5 µg/m³ | Eastern Europe, 16 to 21 December 2025 |
| 24 Jan 2026 | 16170.3 µg/m³ | Europe, January and February 2026 |
| 10 Mar 2025 | 16068.9 µg/m³ | Germany, Poland and 25 more countries, March 2025 |
| 20 Jan 2026 | 16068.5 µg/m³ | Europe, January and February 2026 |
| 1 Jan 2023 | 16068.4 µg/m³ | Eastern Europe, January 2023 |
| 25 Jan 2026 | 15966.3 µg/m³ | Europe, January and February 2026 |
| 1 Feb 2024 | 15966.2 µg/m³ | Europe, 27 January to 2 February 2024 |
| 17 Dec 2025 | 15865.6 µg/m³ | Eastern Europe, 16 to 21 December 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, Cluj-Napoca, Romania, 1 Jan 2023 – 10 Oct 2026. Monitor data from EEA, via OpenAQ and from the publisher directly; sources listed at smogrank.com/sources. smogrank.com/ro/cluj-napoca/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.
Cluj-Napoca 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).