Guernsey Weather Fox

Seven day Guernsey weather forecast for 18 December 2025

Thursday

Weather

Wind and rain, lots of both. The rain will be intermittent but some of it heavy. The wind will be the most brutal, coming from a S’ly direction… strong force 6 in the morning, force 7 in the afternoon, then relaxing to a force 4-5 W’ly overnight. Despite the general nastiness, the air will be very mild… around 13°C throughout the day, gradually falling to 8 or 9°C overnight.

Surf and the Water

Low tide will be at 11:30am and high tide will be around 8m at 5:30pm. The crazy strong winds will make the surf conditions very difficult, even though the west-coast waves will be 8-10 feet and super-clean. The north coast will also have great waves but that wind will be just as hard to deal with. Harcore windsurfers will be loving it though.

Friday

Weather

Much finer weather… a few bubbly clouds that could possibly squeeze out a brief shower (but most likely won’t). The breeze will be a moderate force 4 W’ly at dawn, relaxing to a light force 3 SW’ly by dusk. A thoroughly pleasant day to go walking, running or cycling after probably being couped inside all day Thursday. The east coast (particularly Town) will be warmest, peaking around 12°C. Beautifully clear and starry overnight as the new moon hides around the other side of the planet. Min temps around 8°C, so not as cold as a clear night could be… this is due to the development of a moderate S’ly breeze.

Surf and the Water

The super-powerful 10 foot swell will be choppy in the morning but reasonably clean on the west coast in the afternoon and super-clean up on the north. For swimmers, the wind and weather will be far more appropriate than on Thursday, but it will be essential to avoid the huge swell, so the east coast will really be the only option. High tides will be a little before sunrise and after sunset. Low tide will be just after midday.

The Weekend

Weather

A sunny and dry Saturday, with a fresh force 5 SSE’ly wind. This will mean that the west coast is most sheltered, although it will still feel pretty breezey even there. Temperatures will peak around 11°C in the daytime and then actually hold around that valuethroughout the night. That’s because a blanket of cloud will lock the mildness in, albeit with some patchy rain at times. That cloudy and occasionally rainy situation will most likely persist through Sunday, whilst the wind relaxes to a moderate force 4 SE’ly. This will likely lead to a cooler day, because the influence of France is not a warm one at this time of year, so the day will probably fall to 10°C through the morning and then 9°C through the afternoon.

Surf and the Water

Tides will be high around dawn and dusk (pretty big thanks to the final new moon of the year… rangling between 8.3m and 8.7m). The west-coast surf will be super-clean, roughly 6-feet on Saturday and 8 feet on Sunday. Probably not big enough for the north coast on Saturday, but it certainly should be on Sunday. Swimming conditions will likely be best at L’Ancresse.

The Weekend

Weather

Winds will be near calm on Monday, moderate SE’ly through Tuesday and then fresh NE’ly through the rest of the week. Temperatures will probably reach double figures on Monday and then remain in single figures thereafter, with Christmas day probably seeing some snow on the hills of Normandy and Brittany. Only rain showers for us I’m afraid though.

Surf and the Water

The surf should be 4 feet and clean on Monday, then the rest of the week is looking much smaller and probably quite messy, due to the most likely wind being a brisk NE’ly. Boxing Day swim conditions will be bracing but the wind direction is good for Cobo, especially as the tide will still be quite high at 11am. Those tides generally quite large throughout the week, all the daylight highs will be in the morning, gradually reducing from 8.6m to 8m.

The next forecast update will most likely be on Saturday evening or Sunday morning…

Previous Weather Fox Forecasts

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Ormering
Lihou Causeway

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