County Roscommon climate

Monthly averages for Roscommon, 2021–2025 · Connacht

Roscommon is inland, between the Shannon and the Suck, so it misses the worst of the Atlantic rain while still being wetter than Leinster. Winter nights are cold and frost is common on the lowlands.

Rain: about 1176 mm falls in a year at Roscommon, on roughly 184 days, making Roscommon the 16th wettest of the 32 counties. October is the wettest month (144 mm) and May the driest (79 mm).

Temperature: July is the warmest month, with afternoons averaging 19°C, and January the coldest, with nights averaging 3°C. Frost is rare.

Sunshine: about 2326 hours a year, the 26th sunniest of the 32 counties. May is the sunniest month (9.7 hours a day) and December the dullest (2.9).

Compare Roscommon with its neighbours →

Rainfall

Average total rainfall each month, in millimetres. 1176 mm a year.

Temperature

Bars run from the average night-time low to the average daytime high, in °C.

Sunshine

Hours of sunshine on an average day in each month. About 2326 hours a year.

Roscommon and its neighbours
County	Rain mm/yr	Rain days	July high	January low	Sun h/yr
Roscommon	1176	184	19°C	3°C	2326
Galway	1424	198	19°C	3°C	2451
Leitrim	1231	192	19°C	3°C	2368
Longford	1194	188	19°C	2°C	2408
Mayo	1442	209	18°C	3°C	2280
Offaly	1064	178	19°C	2°C	2409
Sligo	1670	237	18°C	2°C	2268
Westmeath	1079	182	19°C	2°C	2442

Recent extremes, 2021–2025

Hottest day: 30.2°C on 18 July 2022
Coldest night: −3.6°C on 9 January 2025
Wettest day: 36.8 mm on 23 November 2024
Wettest month: October 2022, 182 mm
Driest month: February 2023, 29 mm

Ireland's all-time records are on the records page.

Roscommon month by month
Month	High °C	Low °C	Rain mm	Rain days	Sun h/day	Wind km/h
January	7	3	81	13	3.7	16
February	9	4	98	15	4.1	19
March	11	4	99	16	5.5	15
April	13	5	82	14	8.2	14
May	16	8	79	15	9.7	13
June	18	11	90	16	9.1	14
July	19	12	97	15	8.4	13
August	19	12	103	16	8.7	15
September	17	11	100	15	6.9	14
October	14	9	144	18	5.0	16
November	10	6	96	16	4.1	16
December	8	4	107	15	2.9	18
Year	13	7	1176	184	2326 h	15

Figures are averages for 2021–2025 at each county town, from the ERA5 weather reanalysis via Open-Meteo. They describe typical lowland weather in each county; hills and exposed coasts are wetter and windier.

Bordering counties: Galway · Leitrim · Longford · Mayo · Offaly · Sligo · Westmeath. All counties: rainfall, temperature, sunshine.