Cardiff Weather in December
December in Cardiff typically sees daytime highs of 10°C (50°F) and nighttime lows of 5°C (41°F). As the wettest month of the year, expect more rainfall than other months. It falls within the winter season.
Rainfall in Cardiff in December
Since this month has the highest rainfall, keep an umbrella with you to handle sudden showers. The climate data from previous years indicates about 19 days of rain, averaging 119 mm (4.7 in) for the month. Expect frequent rainfall this month, and not just light drizzle. When it rains, it tends to come down hard.
Temperature in Cardiff in December
Daytime temperatures in Cardiff reach 10°C (50°F) in December, dropping to 5°C (41°F) at night. Experience the winter season in December. The days stay cool from start to finish. Layering up well will make outdoor time much more comfortable. With lows around 5°C (41°F), nights are cold. The upside is that cool, crisp nights are often the best for a deep sleep.
Sunshine in Cardiff in December
With limited sunshine this month, there are about 49 hours of sun. It's ideal for those who prefer a cooler, cloudier climate.
Wind Speed in Cardiff 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 Cardiff.
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 Cardiff's climate page.
Cardiff Temperature in December
Min Temperature
5°C (41°F)
Max Temperature
10°C (50°F)
Water Temperature
10°C (50°F)
Chance of Rain
65%
Precipitation
119 mm (4.7 in)
Rainy days
19 days
Humidity
89%
Windspeed
5 m/s (10 knots)
Sunshine
49 hours
Percentage Sunshine
19%
Daily Historical Temperatures
50-year average (1976-2025)
Based on our historical records, temperatures in Cardiff typically stay consistent throughout December, with daily highs averaging around 10°C (50°F). Nights are cold, with lows around 4°C (39°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 Cardiff in December
Browse day-by-day weather records for Cardiff spanning 51 years. Select any month and year to see actual temperatures, rainfall, and conditions recorded on each day.
Cardiff historical weather extremes in December
Our historical data for Cardiff spans 1976 to 2025, revealing these weather extremes.
- The hottest December day on record in Cardiff reached 17°C (63°F) (December 2, 1985).
- On December 7, 2010, Cardiff saw its coldest December day with temperatures maxing out at -3°C (27°F).
- Cardiff registered its coldest December night on December 12, 1981, with temperatures dropping to -8°C (18°F).
- The wettest December day on record brought 70 mm (2.8 in) of precipitation to Cardiff (December 14, 1989).
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 →
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What to Wear in Cardiff in December
Dress warmly and in layers for your trip to Cardiff 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. With limited sunshine expected, sunglasses aren't a priority for packing.What To Do in Cardiff 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 Cardiff's climate page.
Temperature Rainfall Sunshine Humidity Wind Speed Water Temp
See the full Cardiff climate overview or explore weather in the United Kingdom.
