December Weather in Cardiff, United Kingdom

Last updated: March 17, 2025

In Cardiff, United Kingdom, December presents a chilly yet captivating atmosphere, with temperatures ranging from a maximum of 13°C (56°F) to a minimum of -4°C (26°F) and an average of 7°C (45°F). The month is characterized by considerable precipitation, totaling 130 mm (5.1 in) across 17 days, contributing to the city’s lush winter landscape. With humidity levels reaching a notable 89%, residents and visitors alike can expect a damp, crisp air that embodies the essence of a traditional Welsh winter. This blend of cool temperatures and frequent rainfall invites cozy gatherings and festive cheer during the holiday season.

December Temperature in Cardiff

As December unfolds in Cardiff, temperatures take a notable dip, with lows dropping to -4°C (26°F) and averages hovering around 7°C (45°F). While the chilly weather may lead to frostier mornings, the milder maximum of 13°C (56°F) still provides a hint of warmth in comparison to earlier winter months. Compared to November's lows of -1°C and a higher average, December signals the onset of winter's full embrace, yet it retains a sense of familiarity as it ushers in the festive spirit. The shift from late autumn to winter means a cozy atmosphere, making it a perfect time for enjoying warm beverages and holiday festivities under Cardiff's twinkling lights.

December Weather in Cardiff: Daily Temperature Highs, Lows, and Averages

The chart illustrates December temperature patterns in Cardiff, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends.
JanFebMarAprMayJunJulAugSepOctNovDec424345485460636258534745
Data source: Temperature data for Cardiff generated using information from the Copernicus Climate Change Service.
Choose your preferred temperature unit
The average of daily temperatures (24 hours) calculated across all days in the month.

December Precipitation in Cardiff

In December, Cardiff experiences a notable increase in precipitation, with an average of 130 mm (5.1 in) of rain across 17 days. This is reflective of a trend towards wetter conditions as the year closes, following November’s 99 mm (3.9 in) over 15 days. The spike in rainfall is indicative of the winter months, contributing to a damp atmosphere that can often cast a grey hue over the city. As temperatures drop, the persistently high precipitation levels underscore the region's characteristic maritime climate, with December standing out as one of the wettest months of the year. This frequent rainfall not only shapes the landscape but also invigorates the lush greenery that Cardiff is known for, making the city a vibrant, albeit soggy, winter destination.

December Precipitation Trends in Cardiff

The chart displays monthly precipitation patterns in Cardiff, with values for each month alongside December's data, which is highlighted for easy comparison. It shows the amount of precipitation, providing insights into how December's conditions compare to those of other months.
JanFebMarAprMayJunJulAugSepOctNovDec751019857798485978113599130
Data source: Precipitation data for December generated using information from the Copernicus Climate Change Service.
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December Humidity in Cardiff

In Cardiff, United Kingdom, December brings a return to the higher humidity levels characteristic of the late autumn months, with an average of 89%. This slight dip from November’s peak of 90% still situates December among the more humid months of the year. Throughout the winter, humidity tends to hover around 88-89%, showcasing a consistent trend of elevated moisture content in the air. Following the summer lows of 70% in July, the onset of winter sees humidity climbing back up, creating a notably damp atmosphere that envelops the city. As the year concludes, Cardiff's humidity not only reflects seasonal transitions but also the city's maritime climate, which keeps it lush and vibrant.

December Average Humidity in Cardiff

This chart illustrates the average monthly humidity levels in Cardiff, with December's data highlighted for easy comparison. It shows the fluctuation in humidity throughout the year, allowing you to see how December's humidity levels compare to other months.
JanFebMarAprMayJunJulAugSepOctNovDec89%88%86%84%80%80%70%73%79%89%90%89%
Data source: Humidity data for December generated using information from the Copernicus Climate Change Service.

December UV Index in Cardiff

In December, Cardiff experiences a low UV Index of 1, indicating minimal exposure to harmful ultraviolet rays. This trend mirrors the beginning of the year in January, where the UV Index remains at a low level, suggesting that residents can enjoy outdoor activities without the pressing concern of sunburn, with an approximate burn time of 45 minutes. As the year progresses, the UV Index rises notably from March to June, peaking at a very high level of 8 in both June and July. However, the downward trend in the remaining months signals a seasonal shift toward lower UV exposure, making December a time for cozy indoor activities rather than sunbathing. For more detailed information on UV patterns throughout the year, visit Cardiff UV Index.

Maximum UV Index Levels in Cardiff for December

The chart shows the monthly maximum UV Index (UVI) for Cardiff in December, representing the highest UV radiation level. The UVI measures the intensity of ultraviolet radiation from the sun, indicating the potential risk of sunburn and UV-related health issues.
JanFebMarAprMayJunJulAugSepOctNovDec124678876421
Data source: Cardiff December UVI data generated using information from the Copernicus Climate Change Service.

UV Risk Categories

  •  Extreme (11+): Avoid the sun, stay in shade.
  •  Very High (8-10): Limit sun exposure.
  •  High (6-7): Use SPF 30+ and protective clothing.
  •  Moderate (3-5): Midday shade recommended.
  •  Low (0-2): No protection needed.

December Sunshine in Cardiff

As the year winds down, December in Cardiff offers a gentle respite with approximately 100 hours of sunshine. This represents a noticeable dip compared to the vibrant spring and summer months, where sunshine peaks at 399 hours in July. The trend of diminishing daylight is evident, as December's hours are significantly lower than the bustling months of May and June, which boast 379 and 355 hours, respectively. While the chilly winter air settles in, Cardiff embraces the cozy ambiance, inviting residents and visitors to find joy in the softer, yet still present, winter sunlight amidst the festivities of the season.

Monthly Sunshine Duration in Cardiff: December Highlighted

The December sunshine duration represents the total number of hours Cardiff experiences direct sunlight during the month of December, excluding cloudy or obstructed periods. This chart compares the sunshine duration of December with the other months of the year.
JanFebMarAprMayJunJulAugSepOctNovDec81h134h192h303h379h355h399h345h279h224h121h100h
Data source: Cardiff December Sunshine duration data generated using information from the Copernicus Climate Change Service.

Chance of Sun in Cardiff During December

As the year draws to a close, the likelihood of sunny weather in Cardiff takes a dip, with December showcasing only a 20% chance of sunshine. This reflects a trend observed throughout the winter months, where sunshine hours are notably lower, particularly when compared to the brighter spring months like April, which boasts a substantial 52% chance. Following November’s promising 31%, December’s figures highlight a significant decrease as the city settles into its colder season. Overall, while some sun may still peek through the clouds, residents and visitors in Cardiff should prepare for a predominantly overcast and chilly month.

Percentage of Sunny Days in December in Cardiff

The chart illustrates the percentage of sunny days in Cardiff throughout the year, with December highlighted. It highlights the variation in sunshine across each month and provides an overview of the typical frequency of sunny days, offering insights into how often Cardiff experiences clear skies throughout the year.
JanFebMarAprMayJunJulAugSepOctNovDec21%23%29%52%33%27%41%30%28%21%31%20%
Data source: Cardiff December chance of sun data, generated using information from the Copernicus Climate Change Service.

Daylight Hours in Cardiff in December

As the year draws to a close, December in Cardiff sees a significant reduction in daylight, offering just 7 hours of sunlight. This marks the lowest point in the annual cycle, following a gradual descent from the 16 hours enjoyed in the peak of summer, particularly in June and July. The steady decline from the longer days of spring and summer culminates in the colder months, where January and February follow closely behind with 8 and 9 hours of daylight, respectively. As we transition into winter, Cardiffians are reminded of the rhythmic ebb and flow of daylight, with each month providing a unique experience of light, from the lengthy brightness of May to the fleeting daylight of December.

Average Daylight Hours in Cardiff for December

The chart illustrates the variation in daylight duration in Cardiff throughout the year, with December highlighted. It shows the monthly changes in daylight hours, calculated by summing the hours between sunrise and sunset.
JanFebMarAprMayJunJulAugSepOctNovDec8h 24m9h 58m11h 55m13h 54m15h 38m16h 32m16h 3m14h 30m12h 35m10h 36m8h 50m7h 53m
Data source: Cardiff daylight hours, calculated by summing the hours between sunrise and sunset for each day.

December Winds in Cardiff

As December sweeps in, Cardiff experiences an uptick in wind activity with an average speed of 5.3 m/s (12 mph), marking a shift from the calmer breezes of the summer months. While early winter still brings a hint of the gentle winds felt in April and July, December's gusts begin to echo the stronger breezes of early spring and late fall. This increase hints at the changing seasons, as Cardiff prepares for the more invigorating weather of the new year, balancing between the milder winds of summer and the more robust conditions to come.

Average December Wind Speed in Cardiff

The chart displays monthly wind speed patterns in Cardiff, with values for each month shown alongside December's data, which is highlighted for easy comparison. It illustrates the average wind speed, offering insights into how December's wind conditions compare to the rest of the year.
JanFebMarAprMayJunJulAugSepOctNovDec5.15.74.83.74.73.53.44.23.74.84.25.3 m/s
Data source: Cardiff December wind data, generated using information from the Copernicus Climate Change Service.

How December Weather in Cardiff Compares to Other Months

The weather in Cardiff changes throughout the year, offering a unique experience in each season. Below is a month-by-month comparison of December's weather with other months, highlighting differences in temperature, precipitation, and other key factors. Click on each section to discover seasonal trends in Cardiff and find detailed weather information for every month.

December typically brings a chillier climate compared to January, with average temperatures ranging from a minimum of -4°C (26°F) to a maximum of 13°C (56°F). In contrast, January features slightly milder temperatures, with a minimum of -3°C (27°F) and an average of 6°C (42°F), but still reaching a peak of 13°C (56°F). Precipitation is more frequent in December, accumulating 130 mm (5.1 in) over 17 days, while January sees a reduction, with 75 mm (3.0 in) falling over just 12 days. Humidity remains fairly consistent between the two months, hovering around 89% in December and slightly decreasing to 88% in January. For more details, you can check out Cardiff weather in January.

December and February present a somewhat similar chill, with both months recording a minimum temperature of -4°C (26°F). However, December generally boasts slightly warmer average highs at 7°C (45°F) compared to February's average of 6°C (44°F). February tends to see a bit more variability, offering a maximum temperature of 15°C (60°F), which is noticeably higher than December’s peak of 13°C (56°F). Precipitation is also a factor; December experiences more rain with 130 mm (5.1 in) over 17 days, while February has 101 mm (4.0 in) spread across 14 days, resulting in a marginally drier month. Humidity levels remain quite similar, with December at 89% and February at 88%. For more detailed weather insights, you can check Cardiff weather in February.

December weather is characterized by chilly temperatures, with a minimum of -4°C (26°F) and an average of 7°C (45°F), while March offers slightly milder conditions with a minimum of -5°C (22°F) but an increased maximum of 18°C (65°F). Both months experience similar average temperatures, but December is generally wetter, receiving 130 mm (5.1 in) of precipitation over 17 days compared to March's 97 mm (3.8 in) across 15 days. Humidity levels are also comparable, with December at 89% and March slightly lower at 86%. For more specific details, check out Cardiff weather in March.

December weather is characterized by colder temperatures, with averages hovering around 7°C (45°F) and a maximum of just 13°C (56°F). It experiences significant precipitation, totaling 130 mm (5.1 in) over about 17 days, along with high humidity levels at 89%. In contrast, April brings milder conditions, where the average temperature rises to 9°C (49°F) and can reach up to 20°C (69°F). Precipitation decreases considerably to 57 mm (2.2 in) over only 10 days, and humidity slightly drops to 84%. For more detailed information about the weather in April, you can check Cardiff weather in April.

December and May present contrasting weather conditions in terms of temperature and precipitation. In December, temperatures can dip as low as -4°C (26°F), with an average of 7°C (45°F) and a maximum of 13°C (56°F). Additionally, the month experiences considerable precipitation, totaling 130 mm (5.1 in) over 17 days, accompanied by high humidity at 89%. In comparison, May boasts a milder climate with temperatures ranging from a minimum of 2°C (35°F) to a maximum of 24°C (76°F), averaging 12°C (54°F). The precipitation in May is also lower, at 79 mm (3.1 in) over 12 days, and the humidity is relatively moderate at 80%. These differences make May a much warmer and drier month compared to the cold, wet December. For more specific details about the weather in Cardiff during May, visit Cardiff weather in May.

December and June present contrasting weather patterns. In December, temperatures can dip to a minimum of -4°C (26°F), with an average of 7°C (45°F) and a maximum of 13°C (56°F). The month experiences significant precipitation, totaling 130 mm (5.1 in) over 17 days, contributing to a high humidity level of 89%. In stark contrast, June sees milder weather with minimum temperatures at 7°C (45°F), averaging around 15°C (60°F), and reaching a maximum of 27°C (82°F). Precipitation in June is lower, at 84 mm (3.3 in) over 12 days, and the humidity is slightly reduced at 80%. For more details on June weather, visit Cardiff weather in June.

In December, the weather is quite chilly, with temperatures ranging from a minimum of -4°C (26°F) to a maximum of 13°C (56°F), and an average temperature of 7°C (45°F). This month also sees significant precipitation, totaling 130 mm (5.1 in) over 17 days, accompanied by high humidity levels at 89%. Conversely, July offers a much warmer climate, with temperatures ranging from a minimum of 9°C (48°F) to a maximum of 28°C (82°F), and an average of 17°C (63°F). The month experiences less rainfall, with a total of 85 mm (3.3 in) over 12 days and a lower humidity level of 70%. For more details on July's weather, you can check Cardiff weather in July.

December and August present contrasting weather patterns. In December, temperatures range from a chilly -4°C (26°F) to a maximum of 13°C (56°F), with an average of 7°C (45°F). This month is characterized by high humidity at 89% and significant precipitation of 130 mm (5.1 in) over 17 days, making it one of the wetter months of the year. In contrast, August enjoys milder temperatures, with lows of 9°C (48°F), an average of 17°C (62°F), and highs reaching 29°C (84°F). Precipitation in August is lower at 97 mm (3.8 in) over 13 days, and the humidity is also more comfortable at 73%. For more details on Cardiff's August weather, you can visit Cardiff weather in August.

The weather in December is notably chillier than in September, with average temperatures ranging from a brisk -4°C (26°F) to a maximum of 13°C (56°F). In contrast, September enjoys milder conditions, with temperatures swinging between 4°C (40°F) and a warm average of 15°C (59°F), reaching peaks of up to 27°C (81°F). Additionally, December experiences more precipitation, with 130 mm (5.1 in) over 17 days compared to September’s 81 mm (3.2 in) across 12 days. Humidity levels are also higher in December at 89%, while September offers a slightly drier atmosphere with humidity at 79%. For more detailed insights about September weather, check out Cardiff weather in September.

December weather is notably colder than in October, with average temperatures ranging from a chilly min of -4°C (26°F) to a max of 13°C (56°F). In contrast, October boasts milder conditions, with temperatures varying from a minimum of 1°C (33°F) to a maximum of 21°C (70°F). While both months experience similar levels of precipitation—130 mm in December and 135 mm in October—December tends to feel wetter with its longer spell of rainy days, averaging 17 compared to October's 16. Humidity remains consistent at 89% for both months, making for a damp atmosphere regardless of the seasonal transition. For more details about October weather, check out Cardiff weather in October.

When comparing the weather between November and December, we see a notable drop in average temperatures and a slight increase in precipitation. In November, temperatures range from a minimum of -1°C (30°F) to a maximum of 16°C (61°F), with an average of 9°C (48°F). This month experiences about 99 mm (3.9 in) of precipitation over 15 days, with humidity levels at 90%. In contrast, December sees colder temperatures, with a minimum of -4°C (26°F) and a maximum of 13°C (56°F), averaging around 7°C (45°F). Additionally, precipitation increases to 130 mm (5.1 in) over 17 days, while humidity remains high at 89%. For more details, you can check Cardiff weather in November.

Compare Cardiff's Climate with Cities Worldwide

Conclusion: What to Expect From December Weather in Cardiff

As December settles in, Cardiff experiences a notable shift in weather compared to other months. This time of year sees cooler temperatures, often dipping into the lower range, with an average that hovers around 7°C (45°F), and occasional drops to -4°C (26°F) at night. The city also faces increased precipitation, with about 17 days of rain, contributing to a chilly, damp atmosphere marked by elevated humidity levels nearing 89%. Such weather patterns set December apart from the milder conditions of the earlier months, making it a time for cozy indoor activities while enjoying the unique charm of Cardiff in winter. For more about Cardiff's climatic nuances, check out Cardiff Climate.