Sea weather in Castlerock in Northern Ireland All the beach weather in Castlerock
All the essential weather information for enjoying the beach in Castlerock in Northern Ireland, for swimming, tanning or water sports! Our sea weather data is reliable, easy to read and updated every day.
Weather: When should you go to the beach in Castlerock over the next 7 days?
Discover the best moment to go to the beach in Castlerock in Northern Ireland this week to enjoy the best weather and calmest sea possible. Our opinion is based on reliable sea weather forecasts in Castlerock. You can see full forecasts by clicking on the day you want to see in the table below.
| Date | Outside temp. | Max wind | Our opinion | Details |
|---|---|---|---|---|
| Monday 15 December 2025 | 40°F to 47°F | 6.8mph | recommended | all the sea weather |
| Tuesday 16 December 2025 | 36°F to 43°F | 11.8mph | discouraged | all the sea weather |
| Wednesday 17 December 2025 | 40°F to 49°F | 13.7mph | not recommended | all the sea weather |
| Thursday 18 December 2025 | 43°F to 47°F | 19.9mph | discouraged | all the sea weather |
| Friday 19 December 2025 | 41°F to 45°F | 21.8mph | discouraged | all the sea weather |
| Saturday 20 December 2025 | 41°F to 49°F | 18.6mph | not recommended | all the sea weather |
| Sunday 21 December 2025 | 43°F to 45°F | 3.7mph | discouraged | all the sea weather |
Sea Weather: Your daily and hourly sea weather in Castlerock
Sea weather on Monday 15 December 2025
On Monday 15 December 2025, the sun will rise at 08:46 and will set at 15:57 on the beach(es) of Castlerock. The outside temperature will be a high of 47°F t and a low of 40°F. There will be little to no precipitation today, so unless you go swimming, you can enjoy the beach and stay dry! The sea will be generally calm, with a wind speed of up to 12.4mph km/h (with gusts up to 18mph). Wave height will be up to 7.2ft today.
| 0:00 | 3:00 | 6:00 | 9:00 | 12:00 | 15:00 | 18:00 | 21:00 | |
| Weather | ||||||||
| Sky condition |  | | |  | | | | |
| Outside temperature | 8°C (46°F) | 8°C (46°F) | 6°C (44°F) | 6°C (43°F) | 7°C (44°F) | 6°C (43°F) | 5°C (40°F) | 6°C (42°F) |
| Perceived temperature | 5°C (41°F) | 5°C (40°F) | 3°C (38°F) | 3°C (37°F) | 4°C (39°F) | 4°C (39°F) | 2°C (36°F) | 3°C (38°F) |
| Precipitation | 0in | 0in | 0in | 0in | 0in | 0in | 0in | 0in |
| Humidity | 82% | 77% | 82% | 82% | 79% | 82% | 85% | 85% |
| Barometric pressure | 999 hPa | 1000 hPa | 1000 hPa | 1002 hPa | 1002 hPa | 1002 hPa | 1003 hPa | 1004 hPa |
| Cloud cover | 39% | 100% | 5% | 16% | 14% | 9% | 7% | 12% |
| Heat index | 8°C (46°F) | 8°C (46°F) | 6°C (44°F) | 6°C (43°F) | 7°C (44°F) | 6°C (43°F) | 5°C (40°F) | 6°C (42°F) |
| Dew point | 5°C (41°F) | 4°C (39°F) | 4°C (38°F) | 3°C (38°F) | 3°C (38°F) | 3°C (37°F) | 2°C (36°F) | 3°C (38°F) |
| Wind | ||||||||
| Speed | 20km/h (12mph) | 17km/h (11mph) | 17km/h (10mph) | 17km/h (10mph) | 14km/h (9mph) | 10km/h (6mph) | 9km/h (6mph) | 11km/h (7mph) |
| Gusts | 28km/h (18mph) | 26km/h (16mph) | 28km/h (17mph) | 29km/h (18mph) | 23km/h (14mph) | 19km/h (12mph) | 19km/h (12mph) | 19km/h (12mph) |
| Direction | 251° WSW | 236° SW | 190° S | 183° S | 189° S | 198° SSW | 201° SSW | 213° SSW |
| Wind chill | 5°C (41°F) | 5°C (40°F) | 3°C (38°F) | 3°C (37°F) | 4°C (39°F) | 4°C (39°F) | 2°C (36°F) | 3°C (38°F) |
| Waves | ||||||||
| Height | 1.9m (6.1ft) | 1.8m (6.0ft) | 1.8m (5.8ft) | 1.8m (5.9ft) | 1.9m (6.4ft) | 2.1m (6.9ft) | 2.2m (7.2ft) | 2.2m (7.3ft) |
| Direction | 297° WNW | 298° WNW | 298° WNW | 305° NW | 304° NW | 304° WNW | 309° NW | 310° NW |
| Period | 13.5 sec. | 13.4 sec. | 13.4 sec. | 14.0 sec. | 14.3 sec. | 15.2 sec. | 15.9 sec. | 15.7 sec. |
| Significant height | 0.6m (2ft) | 0.4m (1.3ft) | 0.3m (1ft) | 0.4m (1.3ft) | 0.4m (1.3ft) | 0.3m (1ft) | 0.3m (1ft) | 0.3m (1ft) |
| Sea water temperature | ||||||||
| Water temperature | 11°C (52°F) | 11°C (52°F) | 11°C (52°F) | 11°C (52°F) | 11°C (52°F) | 11°C (52°F) | 11°C (52°F) | 11°C (52°F) |
Sea weather on Tuesday 16 December 2025
On Tuesday 16 December 2025, the sun will rise at 08:47 and will set at 15:57 on the beach(es) of Castlerock. The outside temperature will be a high of 43°F t and a low of 36°F. There will be little to no precipitation today, so unless you go swimming, you can enjoy the beach and stay dry! The sea will be generally calm, with a wind speed of up to 11.8mph km/h (with gusts up to 21.8mph). Wave height will be up to 7.2ft today.
| 0:00 | 3:00 | 6:00 | 9:00 | 12:00 | 15:00 | 18:00 | 21:00 | |
| Weather | ||||||||
| Sky condition | | | | | | | | |
| Outside temperature | 6°C (42°F) | 6°C (42°F) | 5°C (41°F) | 5°C (40°F) | 5°C (40°F) | 4°C (40°F) | 3°C (37°F) | 4°C (38°F) |
| Perceived temperature | 3°C (38°F) | 3°C (37°F) | 2°C (35°F) | 1°C (34°F) | 1°C (34°F) | 1°C (33°F) | -2°C (29°F) | -1°C (31°F) |
| Precipitation | 0in | 0in | 0in | 0in | 0in | 0in | 0in | 0in |
| Humidity | 84% | 83% | 84% | 83% | 82% | 81% | 87% | 88% |
| Barometric pressure | 1005 hPa | 1006 hPa | 1008 hPa | 1010 hPa | 1011 hPa | 1012 hPa | 1013 hPa | 1014 hPa |
| Cloud cover | 19% | 7% | 11% | 5% | 4% | 4% | 5% | 8% |
| Heat index | 6°C (42°F) | 6°C (42°F) | 5°C (41°F) | 5°C (40°F) | 5°C (40°F) | 4°C (40°F) | 3°C (37°F) | 4°C (38°F) |
| Dew point | 3°C (38°F) | 3°C (38°F) | 3°C (37°F) | 2°C (36°F) | 2°C (35°F) | 1°C (34°F) | 1°C (33°F) | 2°C (35°F) |
| Wind | ||||||||
| Speed | 12km/h (7mph) | 13km/h (8mph) | 16km/h (10mph) | 15km/h (10mph) | 16km/h (10mph) | 16km/h (10mph) | 16km/h (10mph) | 19km/h (12mph) |
| Gusts | 20km/h (12mph) | 22km/h (14mph) | 29km/h (18mph) | 28km/h (18mph) | 30km/h (18mph) | 33km/h (21mph) | 34km/h (21mph) | 35km/h (22mph) |
| Direction | 221° SW | 225° SW | 223° SW | 218° SW | 205° SSW | 205° SSW | 184° S | 173° S |
| Wind chill | 3°C (38°F) | 3°C (37°F) | 2°C (35°F) | 1°C (34°F) | 1°C (34°F) | 1°C (33°F) | -2°C (29°F) | -1°C (31°F) |
| Waves | ||||||||
| Height | 2.2m (7.2ft) | 2.1m (6.9ft) | 2.0m (6.5ft) | 1.9m (6.2ft) | 1.8m (5.9ft) | 1.9m (6.3ft) | 2.0m (6.5ft) | 1.9m (6.3ft) |
| Direction | 306° NW | 305° NW | 304° WNW | 302° WNW | 303° WNW | 304° WNW | 304° NW | 303° WNW |
| Period | 14.9 sec. | 14.7 sec. | 14.8 sec. | 14.7 sec. | 14.5 sec. | 14.4 sec. | 14.2 sec. | 14.1 sec. |
| Significant height | 0.3m (1ft) | 0.4m (1.3ft) | 0.5m (1.6ft) | 0.6m (2ft) | 0.7m (2.3ft) | 0.8m (2.6ft) | 0.7m (2.3ft) | 0.6m (2ft) |
| Sea water temperature | ||||||||
| Water temperature | 11°C (52°F) | 11°C (52°F) | 11°C (52°F) | 11°C (52°F) | 11°C (52°F) | 11°C (52°F) | 11°C (52°F) | 11°C (52°F) |
Sea weather on Wednesday 17 December 2025
On Wednesday 17 December 2025, the sun will rise at 08:48 and will set at 15:58 on the beach(es) of Castlerock. The outside temperature will be a high of 49°F t and a low of 40°F. There will be little to no precipitation today, so unless you go swimming, you can enjoy the beach and stay dry! Be careful, the sea will be generally rough with a wind speed of up to 28mph km/h (with gusts up to 29.8mph). Wave height will be up to 6.2ft today.
| 0:00 | 3:00 | 6:00 | 9:00 | 12:00 | 15:00 | 18:00 | 21:00 | |
| Weather | ||||||||
| Sky condition | | |  |  | |  | |  |
| Outside temperature | 4°C (39°F) | 5°C (42°F) | 6°C (43°F) | 8°C (46°F) | 8°C (47°F) | 8°C (47°F) | 8°C (46°F) | 9°C (47°F) |
| Perceived temperature | -1°C (31°F) | 0°C (33°F) | 1°C (33°F) | 3°C (37°F) | 5°C (40°F) | 6°C (42°F) | 7°C (44°F) | 5°C (42°F) |
| Precipitation | 0in | 0in | 0in | 0in | 0in | 0in | 0in | 0in |
| Humidity | 86% | 80% | 87% | 87% | 89% | 93% | 92% | 86% |
| Barometric pressure | 1013 hPa | 1011 hPa | 1007 hPa | 1006 hPa | 1005 hPa | 1005 hPa | 1004 hPa | 1005 hPa |
| Cloud cover | 100% | 84% | 100% | 91% | 100% | 100% | 100% | 100% |
| Heat index | 4°C (39°F) | 5°C (42°F) | 6°C (43°F) | 8°C (46°F) | 8°C (47°F) | 8°C (47°F) | 8°C (46°F) | 9°C (47°F) |
| Dew point | 2°C (35°F) | 2°C (36°F) | 4°C (40°F) | 6°C (42°F) | 7°C (44°F) | 7°C (45°F) | 7°C (44°F) | 6°C (43°F) |
| Wind | ||||||||
| Speed | 23km/h (15mph) | 32km/h (20mph) | 45km/h (28mph) | 38km/h (24mph) | 30km/h (18mph) | 17km/h (11mph) | 9km/h (5mph) | 22km/h (14mph) |
| Gusts | 40km/h (25mph) | 48km/h (30mph) | 47km/h (29mph) | 42km/h (26mph) | 46km/h (28mph) | 28km/h (17mph) | 15km/h (9mph) | 34km/h (21mph) |
| Direction | 172° S | 177° S | 182° S | 186° S | 187° S | 194° SSW | 178° S | 248° WSW |
| Wind chill | -1°C (31°F) | 0°C (33°F) | 1°C (33°F) | 3°C (37°F) | 5°C (40°F) | 6°C (42°F) | 7°C (44°F) | 5°C (42°F) |
| Waves | ||||||||
| Height | 1.8m (5.8ft) | 1.6m (5.3ft) | 1.7m (5.4ft) | 1.9m (6.2ft) | 1.7m (5.7ft) | 1.4m (4.8ft) | 1.2m (4.1ft) | 1.3m (4.2ft) |
| Direction | 303° WNW | 300° WNW | 300° WNW | 300° WNW | 297° WNW | 296° WNW | 297° WNW | 293° WNW |
| Period | 14.0 sec. | 13.7 sec. | 13.3 sec. | 13.0 sec. | 13.0 sec. | 13.0 sec. | 12.8 sec. | 12.5 sec. |
| Significant height | 0.7m (2.3ft) | 0.8m (2.6ft) | 1.7m (5.6ft) | 1.9m (6.2ft) | 1.2m (3.9ft) | 0.5m (1.6ft) | 0.6m (2ft) | 0.8m (2.6ft) |
| Sea water temperature | ||||||||
| Water temperature | 11°C (52°F) | 11°C (52°F) | 11°C (52°F) | 11°C (52°F) | 11°C (52°F) | 11°C (52°F) | 11°C (52°F) | 11°C (52°F) |
Sea weather on Thursday 18 December 2025
On Thursday 18 December 2025, the sun will rise at 08:49 and will set at 15:58 on the beach(es) of Castlerock. The outside temperature will be a high of 47°F t and a low of 43°F. Precipitation is in the forecast (0.2in throughout the day): choose the right time to go to the beach and dodge the raindrops. The sea will be generally calm, with a wind speed of up to 19.9mph km/h (with gusts up to 28mph). Wave height will be up to 13.5ft today.
| 0:00 | 3:00 | 6:00 | 9:00 | 12:00 | 15:00 | 18:00 | 21:00 | |
| Weather | ||||||||
| Sky condition | | | | |  | | | |
| Outside temperature | 8°C (46°F) | 6°C (43°F) | 6°C (43°F) | 7°C (45°F) | 8°C (47°F) | 8°C (47°F) | 7°C (45°F) | 7°C (45°F) |
| Perceived temperature | 4°C (39°F) | 3°C (37°F) | 3°C (37°F) | 4°C (39°F) | 5°C (41°F) | 7°C (45°F) | 3°C (38°F) | 3°C (37°F) |
| Precipitation | 0in | 0in | 0in | 0in | 0.1in | 0in | 0in | 0in |
| Humidity | 80% | 90% | 92% | 86% | 95% | 95% | 90% | 90% |
| Barometric pressure | 1006 hPa | 1007 hPa | 1004 hPa | 1002 hPa | 995 hPa | 987 hPa | 988 hPa | 991 hPa |
| Cloud cover | 8% | 24% | 34% | 87% | 100% | 100% | 100% | 100% |
| Heat index | 8°C (46°F) | 6°C (43°F) | 6°C (43°F) | 7°C (45°F) | 8°C (47°F) | 8°C (47°F) | 7°C (45°F) | 7°C (45°F) |
| Dew point | 4°C (40°F) | 5°C (40°F) | 5°C (41°F) | 5°C (41°F) | 7°C (45°F) | 7°C (45°F) | 5°C (42°F) | 6°C (43°F) |
| Wind | ||||||||
| Speed | 22km/h (14mph) | 15km/h (10mph) | 19km/h (12mph) | 19km/h (12mph) | 22km/h (13mph) | 6km/h (4mph) | 22km/h (14mph) | 32km/h (20mph) |
| Gusts | 34km/h (21mph) | 27km/h (17mph) | 32km/h (20mph) | 30km/h (19mph) | 33km/h (20mph) | 9km/h (5mph) | 33km/h (20mph) | 45km/h (28mph) |
| Direction | 218° SW | 167° SSE | 156° SSE | 136° SE | 100° E | 254° WSW | 289° WNW | 286° WNW |
| Wind chill | 4°C (39°F) | 3°C (37°F) | 3°C (37°F) | 4°C (39°F) | 5°C (41°F) | 7°C (45°F) | 3°C (38°F) | 3°C (37°F) |
| Waves | ||||||||
| Height | 1.9m (6.1ft) | 3.5m (11.5ft) | 4.1m (13.4ft) | 4.0m (13.1ft) | 3.8m (12.6ft) | 3.7m (12.2ft) | 3.5m (11.5ft) | 3.2m (10.6ft) |
| Direction | 298° WNW | 314° NW | 313° NW | 313° NW | 310° NW | 311° NW | 311° NW | 309° NW |
| Period | 13.4 sec. | 20.9 sec. | 20.6 sec. | 20.6 sec. | 19.5 sec. | 19.2 sec. | 18.8 sec. | 17.9 sec. |
| Significant height | 0.8m (2.6ft) | 0.8m (2.6ft) | 0.5m (1.6ft) | 0.6m (2ft) | 1.2m (3.9ft) | 0.9m (3ft) | 1.0m (3.3ft) | 1.3m (4.3ft) |
| Sea water temperature | ||||||||
| Water temperature | 11°C (52°F) | 11°C (52°F) | 11°C (52°F) | 11°C (52°F) | 11°C (52°F) | 11°C (52°F) | 11°C (52°F) | 11°C (52°F) |
Sea weather on Friday 19 December 2025
On Friday 19 December 2025, the sun will rise at 08:49 and will set at 15:58 on the beach(es) of Castlerock. The outside temperature will be a high of 45°F t and a low of 41°F. There will be little to no precipitation today, so unless you go swimming, you can enjoy the beach and stay dry! The sea will be generally calm, with a wind speed of up to 21.8mph km/h (with gusts up to 32.3mph). Wave height will be up to 10.2ft today.
| 0:00 | 3:00 | 6:00 | 9:00 | 12:00 | 15:00 | 18:00 | 21:00 | |
| Weather | ||||||||
| Sky condition | | | |  | | | | |
| Outside temperature | 7°C (44°F) | 6°C (43°F) | 5°C (42°F) | 5°C (41°F) | 6°C (43°F) | 6°C (43°F) | 6°C (42°F) | 7°C (44°F) |
| Perceived temperature | 2°C (36°F) | 2°C (35°F) | 1°C (34°F) | 0°C (33°F) | 1°C (35°F) | 1°C (34°F) | 1°C (33°F) | 2°C (35°F) |
| Precipitation | 0in | 0in | 0in | 0in | 0in | 0in | 0in | 0in |
| Humidity | 74% | 68% | 74% | 81% | 78% | 79% | 83% | 84% |
| Barometric pressure | 996 hPa | 999 hPa | 1002 hPa | 1005 hPa | 1006 hPa | 1007 hPa | 1007 hPa | 1005 hPa |
| Cloud cover | 100% | 76% | 38% | 85% | 24% | 59% | 68% | 100% |
| Heat index | 7°C (44°F) | 6°C (43°F) | 5°C (42°F) | 5°C (41°F) | 6°C (43°F) | 6°C (43°F) | 6°C (42°F) | 7°C (44°F) |
| Dew point | 3°C (37°F) | 1°C (34°F) | 1°C (34°F) | 2°C (36°F) | 2°C (36°F) | 3°C (37°F) | 3°C (37°F) | 4°C (40°F) |
| Wind | ||||||||
| Speed | 35km/h (22mph) | 30km/h (19mph) | 26km/h (16mph) | 29km/h (18mph) | 29km/h (18mph) | 31km/h (19mph) | 30km/h (19mph) | 35km/h (22mph) |
| Gusts | 50km/h (31mph) | 46km/h (29mph) | 41km/h (26mph) | 45km/h (28mph) | 44km/h (28mph) | 49km/h (30mph) | 30km/h (19mph) | 52km/h (33mph) |
| Direction | 287° WNW | 253° WSW | 224° SW | 218° SW | 216° SW | 206° SSW | 192° SSW | 183° S |
| Wind chill | 2°C (36°F) | 2°C (35°F) | 1°C (34°F) | 0°C (33°F) | 1°C (35°F) | 1°C (34°F) | 1°C (33°F) | 2°C (35°F) |
| Waves | ||||||||
| Height | 3.0m (10.0ft) | 2.8m (9.3ft) | 2.8m (9.2ft) | 3.1m (10.0ft) | 2.6m (8.6ft) | 2.3m (7.7ft) | 2.2m (7.1ft) | 2.1m (6.8ft) |
| Direction | 309° NW | 311° NW | 308° NW | 309° NW | 310° NW | 307° NW | 308° NW | 308° NW |
| Period | 17.6 sec. | 17.3 sec. | 7.2 sec. | 16.0 sec. | 15.6 sec. | 14.8 sec. | 14.5 sec. | 14.3 sec. |
| Significant height | 1.0m (3.3ft) | 0.5m (1.6ft) | 1.8m (5.9ft) | 1.0m (3.3ft) | 0.7m (2.3ft) | 0.9m (3ft) | 0.8m (2.6ft) | 0.8m (2.6ft) |
| Sea water temperature | ||||||||
| Water temperature | 11°C (52°F) | 11°C (52°F) | 11°C (52°F) | 11°C (52°F) | 11°C (52°F) | 11°C (52°F) | 11°C (52°F) | 11°C (52°F) |
Sea weather on Saturday 20 December 2025
On Saturday 20 December 2025, the sun will rise at 08:50 and will set at 15:59 on the beach(es) of Castlerock. The outside temperature will be a high of 49°F t and a low of 41°F. Precipitation is in the forecast (0.1in throughout the day): choose the right time to go to the beach and dodge the raindrops. Be careful, the sea will be generally rough with a wind speed of up to 27.3mph km/h (with gusts up to 31.7mph). Wave height will be up to 7.5ft today.
| 0:00 | 3:00 | 6:00 | 9:00 | 12:00 | 15:00 | 18:00 | 21:00 | |
| Weather | ||||||||
| Sky condition | | | | | | | | |
| Outside temperature | 8°C (46°F) | 9°C (49°F) | 9°C (49°F) | 9°C (47°F) | 5°C (41°F) | 6°C (42°F) | 5°C (41°F) | 5°C (42°F) |
| Perceived temperature | 3°C (38°F) | 5°C (41°F) | 5°C (41°F) | 4°C (40°F) | 1°C (34°F) | 1°C (34°F) | -0°C (32°F) | 1°C (33°F) |
| Precipitation | 0in | 0in | 0in | 0.1in | 0in | 0in | 0in | 0in |
| Humidity | 86% | 85% | 82% | 86% | 87% | 80% | 81% | 83% |
| Barometric pressure | 1002 hPa | 999 hPa | 996 hPa | 994 hPa | 996 hPa | 995 hPa | 996 hPa | 996 hPa |
| Cloud cover | 100% | 100% | 100% | 100% | 50% | 73% | 30% | 42% |
| Heat index | 8°C (46°F) | 9°C (49°F) | 9°C (49°F) | 9°C (47°F) | 5°C (41°F) | 6°C (42°F) | 5°C (41°F) | 5°C (42°F) |
| Dew point | 6°C (42°F) | 7°C (44°F) | 6°C (43°F) | 6°C (43°F) | 3°C (37°F) | 3°C (37°F) | 2°C (36°F) | 3°C (37°F) |
| Wind | ||||||||
| Speed | 35km/h (22mph) | 36km/h (23mph) | 44km/h (27mph) | 32km/h (20mph) | 19km/h (12mph) | 31km/h (19mph) | 32km/h (20mph) | 30km/h (18mph) |
| Gusts | 51km/h (32mph) | 38km/h (23mph) | 49km/h (30mph) | 46km/h (29mph) | 30km/h (19mph) | 47km/h (29mph) | 34km/h (21mph) | 44km/h (27mph) |
| Direction | 181° S | 182° S | 181° S | 213° SSW | 201° SSW | 197° SSW | 192° SSW | 190° S |
| Wind chill | 3°C (38°F) | 5°C (41°F) | 5°C (41°F) | 4°C (40°F) | 1°C (34°F) | 1°C (34°F) | -0°C (32°F) | 1°C (33°F) |
| Waves | ||||||||
| Height | 2.0m (6.7ft) | 2.0m (6.5ft) | 1.9m (6.3ft) | 1.9m (6.2ft) | 1.9m (6.3ft) | 1.9m (6.3ft) | 2.3m (7.6ft) | 2.2m (7.2ft) |
| Direction | 304° WNW | 304° WNW | 305° NW | 306° NW | 301° WNW | 301° WNW | 308° NW | 305° NW |
| Period | 13.9 sec. | 13.5 sec. | 13.2 sec. | 12.9 sec. | 12.4 sec. | 12.3 sec. | 13.2 sec. | 12.4 sec. |
| Significant height | 0.8m (2.6ft) | 0.9m (3ft) | 1.1m (3.6ft) | 1.0m (3.3ft) | 0.8m (2.6ft) | 0.8m (2.6ft) | 0.5m (1.6ft) | 0.7m (2.3ft) |
| Sea water temperature | ||||||||
| Water temperature | 11°C (52°F) | 11°C (52°F) | 11°C (52°F) | 11°C (52°F) | 11°C (52°F) | 11°C (52°F) | 11°C (52°F) | 11°C (52°F) |
Sea weather on Sunday 21 December 2025
On Sunday 21 December 2025, the sun will rise at 08:51 and will set at 15:59 on the beach(es) of Castlerock. The outside temperature will be a high of 45°F t and a low of 43°F. There will be little to no precipitation today, so unless you go swimming, you can enjoy the beach and stay dry! The sea will be generally calm, with a wind speed of up to 18mph km/h (with gusts up to 26.1mph). Wave height will be up to 11.8ft today.
| 0:00 | 3:00 | 6:00 | 9:00 | 12:00 | 15:00 | 18:00 | 21:00 | |
| Weather | ||||||||
| Sky condition | | | | | |  | |  |
| Outside temperature | 6°C (42°F) | 6°C (43°F) | 6°C (43°F) | 6°C (43°F) | 7°C (44°F) | 7°C (44°F) | 6°C (43°F) | 6°C (43°F) |
| Perceived temperature | 1°C (34°F) | 2°C (35°F) | 2°C (36°F) | 5°C (41°F) | 5°C (41°F) | 4°C (39°F) | 6°C (43°F) | 5°C (41°F) |
| Precipitation | 0in | 0in | 0in | 0in | 0in | 0.1in | 0in | 0in |
| Humidity | 87% | 89% | 85% | 89% | 86% | 88% | 83% | 86% |
| Barometric pressure | 995 hPa | 995 hPa | 995 hPa | 997 hPa | 998 hPa | 999 hPa | 1001 hPa | 1004 hPa |
| Cloud cover | 90% | 66% | 90% | 87% | 86% | 100% | 85% | 100% |
| Heat index | 6°C (42°F) | 6°C (43°F) | 6°C (43°F) | 6°C (43°F) | 7°C (44°F) | 7°C (44°F) | 6°C (43°F) | 6°C (43°F) |
| Dew point | 4°C (38°F) | 4°C (40°F) | 4°C (39°F) | 4°C (40°F) | 5°C (40°F) | 5°C (41°F) | 4°C (38°F) | 4°C (39°F) |
| Wind | ||||||||
| Speed | 27km/h (17mph) | 29km/h (18mph) | 18km/h (11mph) | 6km/h (4mph) | 10km/h (6mph) | 15km/h (10mph) | 3km/h (2mph) | 6km/h (4mph) |
| Gusts | 38km/h (24mph) | 42km/h (26mph) | 30km/h (19mph) | 10km/h (6mph) | 15km/h (9mph) | 24km/h (15mph) | 5km/h (3mph) | 11km/h (7mph) |
| Direction | 179° S | 179° S | 160° SSE | 234° SW | 240° WSW | 277° W | 213° SSW | 131° SE |
| Wind chill | 1°C (34°F) | 2°C (35°F) | 2°C (36°F) | 5°C (41°F) | 5°C (41°F) | 4°C (39°F) | 6°C (43°F) | 5°C (41°F) |
| Waves | ||||||||
| Height | 2.1m (7.0ft) | 3.3m (10.7ft) | 3.6m (12.0ft) | 3.6m (11.8ft) | 3.1m (10.3ft) | 2.7m (8.9ft) | 2.4m (8.0ft) | 2.3m (7.4ft) |
| Direction | 302° WNW | 306° NW | 313° NW | 317° NW | 320° NW | 319° NW | 320° NW | 319° NW |
| Period | 12.0 sec. | 11.8 sec. | 11.8 sec. | 11.5 sec. | 10.9 sec. | 10.5 sec. | 10.0 sec. | 9.5 sec. |
| Significant height | 0.3m (1ft) | 1.7m (5.6ft) | 1.7m (5.6ft) | 1.6m (5.2ft) | 1.3m (4.3ft) | 1.2m (3.9ft) | 1.1m (3.6ft) | 1.1m (3.6ft) |
| Sea water temperature | ||||||||
| Water temperature | 11°C (52°F) | 11°C (52°F) | 11°C (52°F) | 11°C (52°F) | 11°C (52°F) | 11°C (52°F) | 11°C (52°F) | 11°C (52°F) |