SmogRank / Ireland / Connacht / Roscommon

Roscommon, month by month

Roscommon has a measured daily mean on 536 days since 29 January 2024. Its worst month was February 2025, at 55 US AQI (11.5 µg/m³), 1,052nd of 2,633 cities on that month's world ranking. Its cleanest was July 2024, at 20 US AQI (3.6 µg/m³).

Every month since 2024

2026too few days for a mean (a year needs 199)189 days measured
Jan45#1,462Feb41#2,138Mar48#1,950Apr18 daysMay27#2,415Jun20 daysJul16 daysAug10 daysSep13 daysOct24#2,357
2025too few days for a mean (a year needs 256)192 days measured
Jan52#1,012Feb55#1,052Mar19 daysApr11 daysMay14 daysJun7 daysJul14 daysAug38#2,249Sep7 daysOct9 daysNov20 daysDec21 days
2024too few days for a mean (a year needs 257)155 days measured
Jan3 daysFeb11 daysMar1 dayApr2 daysMay37#1,829Jun17 daysJul20#2,484Aug7 daysSepnoneOct14 daysNov52#974Dec18 days
Each square is a month's mean PM2.5 in US AQI from Roscommon'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 Roscommon 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

23 months
MonthWhy
Sep 202613 of 30 days measured; a month needs 21. The others: 17 with readings for part of the day (a day needs 18 hours).
Aug 202610 of 31 days measured; a month needs 22. The others: 21 with readings for part of the day (a day needs 18 hours).
Jul 202616 of 31 days measured; a month needs 22. The others: 2 with no readings from the monitor, 13 with readings for part of the day (a day needs 18 hours).
Jun 202620 of 30 days measured; a month needs 21. The others: 10 with readings for part of the day (a day needs 18 hours).
Apr 202618 of 30 days measured; a month needs 21. The others: 1 with no readings from the monitor, 11 with readings for part of the day (a day needs 18 hours).
Dec 202521 of 31 days measured; a month needs 22. The others: 10 with readings for part of the day (a day needs 18 hours).
Nov 202520 of 30 days measured; a month needs 21. The others: 10 with readings for part of the day (a day needs 18 hours).
Oct 20259 of 31 days measured; a month needs 22. The others: 6 with no readings from the monitor, 16 with readings for part of the day (a day needs 18 hours).
Sep 20257 of 30 days measured; a month needs 21. The others: 23 with readings for part of the day (a day needs 18 hours).
Jul 202514 of 31 days measured; a month needs 22. The others: 17 with readings for part of the day (a day needs 18 hours).
Jun 20257 of 30 days measured; a month needs 21. The others: 23 with readings for part of the day (a day needs 18 hours).
May 202514 of 31 days measured; a month needs 22. The others: 1 with no readings from the monitor, 16 with readings for part of the day (a day needs 18 hours).
Apr 202511 of 30 days measured; a month needs 21. The others: 19 with readings for part of the day (a day needs 18 hours).
Mar 202519 of 31 days measured; a month needs 22. The others: 12 with readings for part of the day (a day needs 18 hours).
Dec 202418 of 31 days measured; a month needs 22. The others: 6 with no readings from the monitor, 7 with readings for part of the day (a day needs 18 hours).
Oct 202414 of 31 days measured; a month needs 22. The others: 17 with readings for part of the day (a day needs 18 hours).
Sep 2024No day measured. The others: 30 with readings for part of the day (a day needs 18 hours).
Aug 20247 of 31 days measured; a month needs 22. The others: 8 with no readings from the monitor, 16 with readings for part of the day (a day needs 18 hours).
Jun 202417 of 30 days measured; a month needs 21. The others: 13 with readings for part of the day (a day needs 18 hours).
Apr 20242 of 30 days measured; a month needs 21. The others: 1 with readings for part of the day (a day needs 18 hours), 27 with readings left out by our checks.
Mar 20241 of 31 days measured; a month needs 22. The others: 16 with no readings from the monitor, 9 with readings for part of the day (a day needs 18 hours), 5 with readings left out by our checks.
Feb 202411 of 29 days measured; a month needs 21. The others: 17 with readings for part of the day (a day needs 18 hours), 1 missing from OpenAQ's archive.
Jan 20243 of 31 days measured; a month needs 22.

A day counts once 18 hours of it are measured; a month needs 70% of its days.

Roscommon's worst months

MonthUS AQIDays measuredWorld rankEpisode
February 2025 5511.5 µg/m³21 of 281,052ndof 2,633–
January 2025 529.9 µg/m³26 of 311,012thof 2,474–
November 2024 529.4 µg/m³26 of 30974thof 2,624–
March 2026 488.7 µg/m³26 of 311,950thof 2,971Europe, 18 to 25 March 2026
January 2026 458.1 µg/m³24 of 311,462ndof 2,617–
February 2026 417.4 µg/m³25 of 282,138thof 2,866–

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.

Roscommon's worst days

DayUS AQIEpisode
6 May 2025 8829.1 µg/m³–
9 Mar 2025 8728.4 µg/m³Germany, Poland and 25 more countries, March 2025
19 Mar 2025 8527.1 µg/m³–
21 Mar 2026 8326.5 µg/m³Europe, 18 to 25 March 2026
20 Mar 2026 8326.4 µg/m³Europe, 18 to 25 March 2026
17 Feb 2025 8024.5 µg/m³–
23 Dec 2025 7923.9 µg/m³–
4 Apr 2025 7622.5 µg/m³–
26 Nov 2024 7220.4 µg/m³–
13 Feb 2025 7220.2 µg/m³–

Daily means, the highest since 29 Jan 2024; 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, Roscommon, Ireland, 29 Jan 2024 – 11 Oct 2026. Monitor data from EEA, via OpenAQ and from the publisher directly; sources listed at smogrank.com/sources. smogrank.com/ie/roscommon/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.

Roscommon now: the last 24 hours, its ranks today and the last 12 months day by day.

Updated 2026-10-12 19:07 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).