County Derry climate

Monthly averages for Derry, 2021–2025 · Ulster

Derry runs from the Foyle lowlands to the Sperrin Mountains, which are wet and snowy in winter. The north coast is cool and breezy; the city and the Roe valley are somewhat drier.

Rain: about 1186 mm falls in a year at Derry, on roughly 206 days, making Derry the 15th wettest of the 32 counties. October is the wettest month (125 mm) and March the driest (79 mm).

Temperature: July is the warmest month, with afternoons averaging 18°C, and January the coldest, with nights averaging 3°C. Frost is rare.

Sunshine: about 2255 hours a year, the 30th sunniest of the 32 counties. May is the sunniest month (9.3 hours a day) and December the dullest (2.6).

Compare Derry with its neighbours →

Rainfall

Average total rainfall each month, in millimetres. 1186 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 2255 hours a year.

Derry and its neighbours
County	Rain mm/yr	Rain days	July high	January low	Sun h/yr
Derry	1186	206	18°C	3°C	2255
Antrim	1047	175	19°C	2°C	2637
Donegal	1211	200	18°C	3°C	2212
Tyrone	1200	200	18°C	2°C	2255

Recent extremes, 2021–2025

Hottest day: 28.4°C on 18 July 2022
Coldest night: −4.5°C on 12 December 2022
Wettest day: 33.4 mm on 3 September 2022
Wettest month: October 2022, 183 mm
Driest month: April 2021, 39 mm

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

Derry month by month
Month	High °C	Low °C	Rain mm	Rain days	Sun h/day	Wind km/h
January	7	3	92	15	3.4	17
February	9	4	96	17	4.2	20
March	10	4	79	15	5.9	16
April	12	5	89	16	8.4	14
May	15	8	85	16	9.3	13
June	17	10	86	18	8.8	14
July	18	12	103	19	7.7	13
August	18	12	110	19	8.7	15
September	16	10	104	16	6.9	14
October	13	9	125	19	4.5	17
November	10	6	93	17	3.6	17
December	8	4	124	18	2.6	18
Year	13	7	1186	206	2255 h	16

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.