SmogRank / Ireland / Leinster / Dún Laoghaire
Dún Laoghaire, month by month
Dún Laoghaire has a measured daily mean on 847 days since 1 January 2023. Its worst month was March 2025, at 57 US AQI (12.5 µg/m³), 1,156th of 2,862 cities on that month's world ranking. Its cleanest was August 2023, at 22 US AQI (4.0 µg/m³).
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
22 months
| Month | Why |
|---|---|
| Aug 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. |
| Jun 2026 | 20 of 30 days measured; a month needs 21. The others: 10 with under 18 hours of readings or readings that failed our checks. |
| Mar 2026 | 3 of 31 days measured; a month needs 22. The others: 28 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 | No day measured. The others: 31 with under 18 hours of readings or readings that failed our checks. |
| Nov 2025 | No day measured. The others: 30 with under 18 hours of readings or readings that failed our checks. |
| Oct 2025 | No day measured. The others: 31 with under 18 hours of readings or readings that failed our checks. |
| Sep 2025 | 6 of 30 days measured; a month needs 21. The others: 24 with under 18 hours of readings or readings that failed our checks. |
| Jul 2025 | 17 of 31 days measured; a month needs 22. The others: 14 with under 18 hours of readings or readings that failed our checks. |
| Jun 2025 | 13 of 30 days measured; a month needs 21. The others: 17 with under 18 hours of readings or readings that failed our checks. |
| May 2025 | 14 of 31 days measured; a month needs 22. The others: 17 with under 18 hours of readings or readings that failed our checks. |
| Apr 2025 | 19 of 30 days measured; a month needs 21. The others: 11 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 | 11 of 31 days measured; a month needs 22. The others: 20 with under 18 hours of readings or readings that failed our checks. |
| Jun 2024 | 9 of 30 days measured; a month needs 21. The others: 21 with under 18 hours of readings or readings that failed our checks. |
| May 2024 | 18 of 31 days measured; a month needs 22. The others: 13 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. |
| Mar 2023 | 11 of 31 days measured; a month needs 22. The others: 20 missing from OpenAQ's archive. |
| Feb 2023 | 2 of 28 days measured; a month needs 20. The others: 25 missing from OpenAQ's archive, 1 with under 18 hours of readings or readings that failed our checks. |
| Jan 2023 | 18 of 31 days measured; a month needs 22. The others: 7 missing from OpenAQ's archive, 6 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.
Dún Laoghaire's worst months
| Month | US AQI | World rank | Episode |
|---|---|---|---|
| March 2025 | 5712.5 µg/m³ | 1,156thof 2,862 | Europe, March 2025 Germany, Poland and 25 more countries, March 2025 |
| February 2025 | 5611.9 µg/m³ | 1,023rdof 2,633 | – |
| November 2024 | 529.9 µg/m³ | 868thof 2,624 | – |
| January 2025 | 509.0 µg/m³ | 1,177thof 2,474 | – |
| January 2024 | 498.9 µg/m³ | 1,039thof 2,385 | – |
| June 2023 | 488.7 µg/m³ | 989thof 1,603 | – |
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.
Dún Laoghaire's worst days
| Day | US AQI | Episode |
|---|---|---|
| 9 Mar 2024 | 11440.8 µg/m³ | – |
| 9 Mar 2025 | 10738.1 µg/m³ | Germany, Poland and 25 more countries, March 2025 |
| 8 Sept 2023 | 9331.5 µg/m³ | United Kingdom, Belgium and 2 more countries, September 2023 |
| 26 Dec 2024 | 9230.9 µg/m³ | – |
| 20 Mar 2025 | 8728.3 µg/m³ | Europe, March 2025 |
| 8 Mar 2024 | 8627.7 µg/m³ | – |
| 10 Mar 2025 | 8527.4 µg/m³ | Germany, Poland and 25 more countries, March 2025 |
| 7 Jan 2024 | 8527.2 µg/m³ | – |
| 12 May 2024 | 8326.5 µg/m³ | – |
| 2 Dec 2023 | 8326.4 µg/m³ | France, Belgium and 2 more countries, November and December 2023 |
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, Dún Laoghaire, Ireland, 1 Jan 2023 – 12 Oct 2026. Monitor data from EEA, via OpenAQ and from the publisher directly; sources listed at smogrank.com/sources. smogrank.com/ie/dun-laoghaire/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.
Dún Laoghaire now: the last 24 hours, its ranks today and the last 12 months day by day.
Updated 2026-10-13 02:07 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).