Monthly climate in Castletown, Isle of Man

Last updated: May 6, 2024

Under the Köppen–Geiger climate classification Castletown features a oceanic climate (Cfb).Temperatures typically range between 7 °C (45 °F) and 15 °C (59 °F) through the year, but rarely can drop to -1 °C (30 °F) or can rise to as high as 19 °C (67 °F).The average annual precipitation amounts to about 1110 mm (43.7 inches) and receives 179 rainy days on the 1 mm (0.04 inches) threshold annually.Castletown enjoys an average of 3241 hours of sunshine throughout the year, and daylight varies from 7 hours 26 minutes to 17 hours 2 minutes per day.

Monthly average temperatures in Castletown, Isle of Man §

The warmest months in Castletown are July, August and September, with daily mean temperatures ranging from 14 to 15 °C (58 - 59 °F) throughout the day. The coldest temperatures usually occur in January, February and March, when daily mean temperatures range from 7 to 8 °C (45 - 46 °F) throughout the day. On average each year, Castletown 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 Castletown, Isle of Man.Generated using Copernicus Climate Change Service information.Data for period from January 2017 to June 2022.
  Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
Maximum 13°C
(56°F)
12°C
(54°F)
11°C
(52°F)
13°C
(56°F)
16°C
(60°F)
17°C
(64°F)
19°C
(67°F)
18°C
(65°F)
19°C
(67°F)
17°C
(63°F)
14°C
(58°F)
13°C
(56°F)
Mean maximum 11°C
(53°F)
11°C
(52°F)
10°C
(51°F)
12°C
(53°F)
14°C
(58°F)
16°C
(60°F)
18°C
(64°F)
17°C
(63°F)
17°C
(63°F)
16°C
(61°F)
14°C
(57°F)
13°C
(55°F)
Average high 9°C
(48°F)
8°C
(47°F)
8°C
(47°F)
9°C
(49°F)
11°C
(52°F)
14°C
(57°F)
15°C
(60°F)
16°C
(61°F)
15°C
(60°F)
13°C
(57°F)
11°C
(52°F)
10°C
(49°F)
Daily mean 8°C
(46°F)
7°C
(45°F)
7°C
(45°F)
8°C
(47°F)
10°C
(51°F)
13°C
(55°F)
14°C
(58°F)
15°C
(59°F)
14°C
(58°F)
13°C
(55°F)
10°C
(51°F)
9°C
(48°F)
Average low 7°C
(44°F)
6°C
(43°F)
6°C
(44°F)
7°C
(46°F)
10°C
(49°F)
12°C
(54°F)
14°C
(57°F)
14°C
(58°F)
13°C
(56°F)
12°C
(53°F)
9°C
(49°F)
8°C
(46°F)
Mean minimum 4°C
(39°F)
3°C
(37°F)
3°C
(38°F)
5°C
(40°F)
7°C
(44°F)
10°C
(51°F)
12°C
(54°F)
13°C
(55°F)
11°C
(52°F)
9°C
(49°F)
6°C
(44°F)
5°C
(41°F)
Minimum 3°C
(38°F)
1°C
(34°F)
-1°C
(30°F)
3°C
(38°F)
5°C
(42°F)
9°C
(49°F)
12°C
(53°F)
12°C
(54°F)
10°C
(51°F)
7°C
(45°F)
6°C
(43°F)
4°C
(39°F)

Compare climate in Castletown with other places

Compare temperature, precipitation, sunshine, UV index in Castletown, Isle of Man with other places around the world.

Monthly average precipitation in Castletown, Isle of Man §

Castletown usually has the most precipitation in October, November and December, with an average of 20 rainy days and 143 mm (5.6 inches) of precipitation per month.The driest months in Castletown are April, May and June. On average, 50 mm (2.0 inches) of precipitation falls during these months.

Monthly average precipitation and precipitation days in Castletown, Isle of Man.Generated using Copernicus Climate Change Service information.Data for period from January 2017 to January 2022.
  Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
Average precipitation mm (inches) 81 (3.2) 106 (4.2) 87 (3.4) 36 (1.4) 44 (1.7) 70 (2.8) 70 (2.8) 94 (3.7) 91 (3.6) 142 (5.6) 143 (5.6) 144 (5.7)
Average precipitation days (≥ 1 mm) 14 18 18 8 9 11 12 15 14 18 20 22

Monthly sunshine hours in Castletown, Isle of Man §

The sunniest months in Castletown are May, June and July, when the sun shines an average of 13 hours 33 minutes a day.Least sunny months in Castletown: January, November and December receive an average of 3 hours 32 minutes of sunshine daily.

Mean monthly sunshine duration, average sunshine hours per day and mean daily daylight hours in Castletown, Isle of Man.Generated using Copernicus Atmosphere Monitoring Service information.Data for period from January 2017 to January 2022.
  Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
Mean monthly sunshine hours 90 161 232 341 418 410 417 375 313 243 131 104
Mean daily daylight hours 8h 0m 9h 46m 11h 54m 14h 5m 16h 1m 17h 2m 16h 29m 14h 45m 12h 38m 10h 28m 8h 30m 7h 26m

Solar UV radiation in Castletown, Isle of Man §

Castletown 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 Castletown UV Index data.

Average daily maximum UV levels by month for Castletown, Isle of Man.Generated using Copernicus Atmosphere Monitoring Service information.Data for period from January 2022 to January 2023.
  Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
UV Index (month maximum) 1 2 3 5 7 8 8 7 5 3 2 1