Belfast Weather in December
December in Belfast typically sees daytime highs of 9°C (48°F) and nighttime lows of 4°C (39°F). Rainfall is also possible this month, so it's worth packing an umbrella. It falls within the winter season.
Rainfall in Belfast in December
The climate data from previous years indicates about 20 days of rain, averaging 95 mm (3.7 in) for the month. Rain falls on many days this month, but usually in relatively small amounts. A light waterproof is more useful than a heavy umbrella.
Temperature in Belfast in December
If you're visiting Belfast in December, expect highs of 9°C (48°F) and overnight lows around 4°C (39°F). The winter season is characteristic of December. Even at the warmest part of the day, temperatures stay low. Dressing warmly from the start is the sensible approach. At 4°C (39°F) overnight, it gets properly cold after dark. On the bright side, cold nights tend to make for excellent sleeping conditions.
Sunshine in Belfast in December
The area sees fewer sunny days, with a projection of about 39 hours of sunshine. This reduced sunlight makes it ideal for those who prefer overcast conditions over bright sunny days.
Wind Speed in Belfast in December
Average wind conditions reach 5 m/s (10 knots) in December. This creates lively weather with fresh winds that make small trees sway noticeably. Remember this is an average: some days are less windy while others have particularly active windy conditions.
Average water temperature in December
At 10°C (50°F), the water is too cold for most people to swim comfortably. A wetsuit is pretty much essential if you plan to go in.Our weather planner can help you find worldwide destinations with pleasant weather during this period. July and August typically offer the best weather for Belfast.
Check the conditions for any month of the year.
For a detailed overview over the year and the best time to visit the United Kingdom, check out our Belfast's climate page.
Belfast Temperature in December
Min Temperature
4°C (39°F)
Max Temperature
9°C (48°F)
Water Temperature
10°C (50°F) *
Chance of Rain
66%
Precipitation
95 mm (3.7 in)
Rainy days
20 days
Humidity
90% *
Windspeed
5 m/s (10 knots) *
Sunshine
39 hours *
Percentage Sunshine
15% *
Daily Historical Temperatures
50-year average (1976-2025)
Based on our historical records, temperatures in Belfast typically stay consistent throughout December, with daily highs averaging around 9°C (48°F). Nights are cold, with lows around 3°C (37°F).
Average temperatures in December
Daily Historical Precipitation
50-year average (1976-2025)
Average daily rainfall for each day of the month based on long-term records.
Average precipitation in December
Historical weather for Belfast in December
Browse day-by-day weather records for Belfast spanning 51 years. Select any month and year to see actual temperatures, rainfall, and conditions recorded on each day.
Belfast historical weather extremes in December
Our historical data for Belfast spans 1976 to 2025, revealing these weather extremes.
- On December 9, 2025, temperatures climbed to 15°C (59°F), marking the warmest December day on record.
- Belfast registered its coldest December night on December 21, 2010, with temperatures dropping to -12°C (10°F).
Best Places in the United Kingdom in December
Find out more about the weather in the United Kingdom and which places have the best travel conditions in this month. See all of the United Kingdom in December →
perfect weather
pleasant
tolerable
unpleasant
poor
What to Wear in Belfast in December
Dress warmly and in layers for your trip to Belfast in December. A good base layer system works wonders. Start with good thermal underwear, add something warm like a fleece sweater, then finish with a waterproof jacket on top. Expect heavy rainfall, so bring good rain protection and waterproof bags. Expect water temperatures of around 10°C (50°F), which is definitely too cold for comfortable swimming. Your luggage space is better used for other items. Sunglasses aren't essential this month, though you might want them for the occasional bright moment.What To Do in Belfast in December
We rated the following activities from 1 (least suitable) to 10 (best) to do.
Check the conditions for any month of the year.
For a detailed overview over the year and the best time to visit the United Kingdom, check out our Belfast's climate page.
Temperature Rainfall Sunshine Humidity Wind Speed Water Temp
See the full Belfast climate overview or explore weather in the United Kingdom.
