Cardiff Weather & Climate: Best Time to Visit
Average temperatures, rainfall, sunshine and the best time to visit Cardiff.
Climate overview of Cardiff
The climate in Cardiff, Wales, United Kingdom, is marked by large temperature swings across the seasons, ranging from 20°C (68°F) in August to 9°C (48°F) in January.
The city has a wet climate, receiving around 1138 mm (45 in) of rainfall per year. Despite the high annual total, it has pleasant summers and cold winters. December is the wettest month. The sunniest month is July, with 6.7 hours of sunshine per day on average.
Cardiff Weather by Month
Pick a month to see the average temperature, rainfall and sunshine in Cardiff - and find the best time to visit.
Monthly Temperature in Cardiff
In Cardiff, temperatures differ significantly between summer and winter months. On average, daytime temperatures range from a pleasant 20°C (68°F) in August to a chilly 9°C (48°F) in January.
Nighttime temperatures range from 14°C (57°F) in August to 4°C (39°F) in January.
Check out our detailed temperature page for more information.
Temperature ranges by month
Rainfall in Cardiff
Cardiff experiences significant rainfall throughout the year, averaging 1138 mm (45 in) of precipitation annually. The wettest period in Cardiff occurs in December, which receives around 119 mm (4.7 in) of precipitation. During the driest month, March, Cardiff experiences moderate rainfall, totaling 76 mm (3 in). The consistent precipitation levels throughout the year contribute to a relatively stable climate. For more details, please visit our Cardiff Precipitation page.
The mean monthly precipitation over the year, including rain, hail, and snow
The average number of days each month with precipitation
Sunshine Hours in Cardiff
In Cardiff, summer days are longer and more sunny, with daily sunshine hours peaking at 6.7 hours in July. As the darker season arrives, the brightness of the sun becomes less. December sees a soft sun for only 1.6 hours per average day.
Visit our detailed sunshine hours page for more information.
Monthly hours of sunshine
Daily hours of sunshine
Daily percentage of sunshine
Water Temperature in Cardiff
The mean water temperature over the year ranges from 7°C (45°F) in February to 16°C (61°F) in August.
Water temperature over the year
Humidity in Cardiff by Month
The city experiences its highest humidity in January, reaching 89%. In June, the humidity drops to its lowest level at 73%. What does this mean? Read our detailed page on humidity levels for further details.
Relative humidity over the year
Wind Speed in Cardiff
The mean wind speed over the year ranges from 4 m/s (8 knots) in May, June, July, August and September to 5 m/s (10 knots) in January, February, March, April, October, November and December. What does this mean?
The mean monthly wind speed over the year (meters per second)
Best Time to Visit Cardiff
Monthly ratings reflect general weather comfort, based on daytime temperature and rainfall. Swimming and winter conditions are highlighted separately where relevant.
- Best overall: July and August
- Warmest weather: July and August
- Most sunshine: May, June and July
- Warmest water temperature: July, August and September, although the water may still feel cool.
- Seasonal pattern: Pleasant summers and cold winters
Frequently asked questions about the climate in Cardiff
What is the best time to visit Cardiff?
July and August typically offer the most optimal weather in Cardiff. In contrast, January, February, November and December tend to have less optimal conditions. Cardiff has pleasant summers and cold winters.
What temperatures can I expect in Cardiff?
Daytime highs range from 9°C (48°F) in January to 20°C (68°F) in August. Nighttime lows range from 4°C (39°F) to 14°C (57°F). Temperatures vary considerably through the year.
How much rain does Cardiff get?
Annual rainfall is around 1138 mm (45 in). December is the wettest month with 119 mm (4.7 in), while March is the driest with 76 mm (3 in).
How sunny is Cardiff?
Cardiff receives around 1,573 hours of sunshine per year. July is the sunniest month with 202 hours, while December is the cloudiest with just 49 hours.
Cardiff 3-Day Forecast
Cardiff on the map
Cardiff is highlighted - select any city to see its climate.
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