nomadseason

Monthly climate in Greencastle, Ireland

Last updated: July 31, 2025

Under the Köppen–Geiger climate classification Greencastle features a oceanic climate (Cfb). Temperatures typically range between 6 °C (44 °F) and 14 °C (58 °F) through the year, but rarely can drop to -1 °C (30 °F) or can rise to as high as 20 °C (69 °F). The average annual precipitation amounts to about 1508 mm (59.4 inches) and receives 219 rainy days on the 1 mm (0.04 inches) threshold annually. Greencastle enjoys an average of 2941 hours of sunshine throughout the year, and daylight varies from 7 hours 13 minutes to 17 hours 17 minutes per day.

Monthly average temperatures in Greencastle, Ireland

The warmest months in Greencastle are July, August and September, with daily mean temperatures ranging from 13 to 14 °C (56 - 58 °F) throughout the day. The coldest temperatures usually occur in January, February and March, when daily mean temperatures range from 6 to 7 °C (44 - 44 °F) throughout the day. On average each year, Greencastle experiences 0 days above 25 °C (77.0 °F) and 0 days below 0 °C (32.0 °F).

Monthly average temperatures with daily means, minimums and maximums for period, average high and low temperatures in Greencastle. Generated using Copernicus Climate Change Service information. Data for period from January 2017 to June 2022.
 JanFebMarAprMayJunJulAugSepOctNovDec
Maximum13°C
(55°F)		12°C
(55°F)		12°C
(55°F)		14°C
(58°F)		17°C
(63°F)		18°C
(65°F)		20°C
(69°F)		20°C
(68°F)		18°C
(64°F)		16°C
(62°F)		14°C
(58°F)		12°C
(54°F)
Mean maximum11°C
(53°F)		11°C
(52°F)		11°C
(52°F)		13°C
(55°F)		15°C
(60°F)		16°C
(61°F)		18°C
(66°F)		18°C
(65°F)		17°C
(63°F)		15°C
(60°F)		13°C
(56°F)		12°C
(53°F)
Average high8°C
(47°F)		8°C
(46°F)		8°C
(47°F)		9°C
(49°F)		11°C
(53°F)		13°C
(56°F)		15°C
(59°F)		15°C
(60°F)		15°C
(59°F)		12°C
(55°F)		10°C
(51°F)		9°C
(48°F)
Daily mean7°C
(44°F)		6°C
(44°F)		7°C
(44°F)		8°C
(47°F)		10°C
(51°F)		12°C
(54°F)		14°C
(57°F)		14°C
(58°F)		13°C
(56°F)		11°C
(53°F)		9°C
(49°F)		8°C
(46°F)
Average low6°C
(42°F)		5°C
(41°F)		5°C
(42°F)		7°C
(45°F)		9°C
(49°F)		11°C
(53°F)		13°C
(56°F)		13°C
(56°F)		12°C
(54°F)		10°C
(51°F)		8°C
(47°F)		6°C
(44°F)
Mean minimum2°C
(36°F)		2°C
(36°F)		2°C
(36°F)		4°C
(39°F)		6°C
(44°F)		9°C
(49°F)		11°C
(52°F)		12°C
(53°F)		10°C
(50°F)		7°C
(45°F)		5°C
(42°F)		3°C
(38°F)
Minimum1°C
(35°F)		1°C
(34°F)		-1°C
(30°F)		2°C
(36°F)		4°C
(40°F)		8°C
(47°F)		10°C
(51°F)		11°C
(52°F)		9°C
(49°F)		5°C
(41°F)		4°C
(40°F)		2°C
(35°F)

Compare climate in Greencastle with other places

Compare temperature, precipitation, sunshine, UV index in Greencastle, Ireland with other places around the world.

Monthly average precipitation in Greencastle, Ireland

Greencastle usually has the most precipitation in August, October and December, with an average of 22 rainy days and 166 mm (6.5 inches) of precipitation per month. The driest months in Greencastle are January, April and May. On average, 82 mm (3.2 inches) of precipitation falls during these months.

Monthly average precipitation and precipitation days in Greencastle. Generated using Copernicus Climate Change Service information. Data for period from January 2017 to January 2022.
 JanFebMarAprMayJunJulAugSepOctNovDec
Average precipitation mm (inches)106 (4.2)135 (5.3)123 (4.8)61 (2.4)79 (3.1)114 (4.5)118 (4.7)165 (6.5)125 (4.9)169 (6.6)150 (5.9)163 (6.4)
Average precipitation days (≥ 1 mm)171819121317162119232222

Monthly sunshine hours in Greencastle, Ireland

The sunniest months in Greencastle are May, June and July, when the sun shines an average of 12 hours 44 minutes a day. Least sunny months in Greencastle: January, November and December receive an average of 2 hours 52 minutes of sunshine daily.

Mean monthly sunshine duration, average sunshine hours per day and mean daily daylight hours in Greencastle. Generated using Copernicus Atmosphere Monitoring Service information. Data for period from January 2017 to January 2022.
 JanFebMarAprMayJunJulAugSepOctNovDec
Mean monthly sunshine hours7014220131239937939235027722111479
Mean daily daylight hours7h 49m9h 40m11h 53m14h 10m16h 12m17h 17m16h 42m14h 52m12h 39m10h 23m8h 20m7h 13m

Solar UV radiation in Greencastle, Ireland

Greencastle experiences the highest level of ultraviolet (UV) radiation in June, July and August, when the maximum UV index can reach values of 7 - 8, which corresponds to the High / Very High category of sun exposure. January, February and December are in the Low exposure category. In these months, the maximum values of the UV index do not exceed 2. For more detailed information, check out our hourly Greencastle UV Index data.

Average daily maximum UV levels by month for Greencastle. Generated using Copernicus Atmosphere Monitoring Service information. Data for period from January 2022 to January 2023.
 JanFebMarAprMayJunJulAugSepOctNovDec
UV Index (month maximum)124568875321