SmogRank / Ireland / Leinster / Dundalk

Dundalk, month by month

Dundalk has a measured daily mean on 166 days since 22 May 2025. Its worst month was August 2026, at 33 US AQI (6.0 µg/m³), 2,462nd of 2,896 cities on that month's world ranking. Its cleanest was September 2026, at 27 US AQI (4.8 µg/m³).

Every month since 2025

2026too few days for a mean (a year needs 199)122 days measured
JannoneFebnoneMarnoneAprnoneMay10 daysJun20 daysJul30#2,540Aug33#2,462Sep27#2,432Oct29#2,075
2025too few days for a mean (a year needs 256)44 days measured
JanFebMarAprMay7 daysJun5 daysJul10 daysAug18 daysSep4 daysOctnoneNovnoneDecnone
Each square is a month's mean PM2.5 in US AQI from Dundalk's measured days, with its place on that month's world ranking under it. A month has a mean once 70% of its days are measured, the rule the monthly rankings use; under that, the square gives the days measured. Each square opens that month's ranking with Dundalk marked; each year, the year's. A dashed square is the running month, so far.
Good0–50
Moderate51–100
Sensitive groups101–150
Unhealthy151–200
Very unhealthy201–300
Hazardous301+

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
MonthWhy
Jun 202620 of 30 days measured; a month needs 21. The others: 10 with under 18 hours of readings or readings that failed our checks.
May 202610 of 31 days measured; a month needs 22. The others: 21 with under 18 hours of readings or readings that failed our checks.
Apr 2026No day measured. The others: 30 with under 18 hours of readings or readings that failed our checks.
Mar 2026No day measured. The others: 31 with under 18 hours of readings or readings that failed our checks.
Feb 2026No day measured. The others: 28 with under 18 hours of readings or readings that failed our checks.
Jan 2026No day measured. The others: 31 with under 18 hours of readings or readings that failed our checks.
Dec 2025No day measured. The others: 31 with under 18 hours of readings or readings that failed our checks.
Nov 2025No day measured. The others: 30 with under 18 hours of readings or readings that failed our checks.
Oct 2025No day measured. The others: 31 with under 18 hours of readings or readings that failed our checks.
Sep 20254 of 30 days measured; a month needs 21. The others: 26 with under 18 hours of readings or readings that failed our checks.
Aug 202518 of 31 days measured; a month needs 22. The others: 13 with under 18 hours of readings or readings that failed our checks.
Jul 202510 of 31 days measured; a month needs 22. The others: 21 with under 18 hours of readings or readings that failed our checks.
Jun 20255 of 30 days measured; a month needs 21. The others: 25 with under 18 hours of readings or readings that failed our checks.
May 20257 of 31 days measured; a month needs 22. The others: 3 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.

Dundalk's worst months

MonthUS AQIDays measuredWorld rank
August 2026 336.0 µg/m³27 of 312,462ndof 2,896
July 2026 305.4 µg/m³30 of 312,540thof 2,784
September 2026 274.8 µg/m³26 of 302,432ndof 2,981

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.

Dundalk's worst days

DayUS AQI
26 Aug 2026 6416.3 µg/m³
16 Jul 2026 6315.4 µg/m³
21 Jun 2025 6114.5 µg/m³
13 Aug 2026 6114.4 µg/m³
17 Jul 2026 6013.8 µg/m³
27 Aug 2026 5913.6 µg/m³
12 Aug 2026 5813.1 µg/m³
15 Jul 2026 5712.2 µg/m³
11 Sept 2026 5511.4 µg/m³
28 May 2026 5511.2 µg/m³

Daily means, the highest since 22 May 2025; 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, Dundalk, Ireland, 22 May 2025 – 11 Oct 2026. Monitor data from EEA, via OpenAQ and from the publisher directly; sources listed at smogrank.com/sources. smogrank.com/ie/dundalk/history (accessed 12 Oct 2026).

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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.

Dundalk 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).