Weather in Cardiff in August 2025
Average weather
Average temperature in Cardiff in August
The temperature in August is +68°F on average, with a range between a maximum of +77°F during the day and a minimum of +48°F at night.
The average maximum temperature goes down 25% by the end of the month, compared with the beginning of the month, from +68°F to +61°F.
Is Cardiff warm or cold in August?
Cardiff is typically mild in August.
Maximum temperatures go down compared to the previous month from +70°F to +68°F. The minimum temperature also goes up from +57°F to +57°F.
Pack a light jacket as it will be warm in the day and cool in the evenings.
August is one of the warmest months in Cardiff, here is the comparison with other months:
Water temperature in Cardiff in August
Water in Cardiff in August is Fresh. It varies from +61°F to +64°F, with an average of +62°F. This is almost similar to the air temperature, which averages +68°F.
The water temperature in August is one of the warmest of the entire year:
Can you swim in Cardiff in August?
Climate in Cardiff in August
| July | August | September | ||||
|---|---|---|---|---|---|---|
| Avg. temperature | ||||||
| +70°F | +68°F | +64°F | ||||
| Min. temperature | ||||||
| +43°F | +45°F | +39°F | ||||
| Max. temperature | ||||||
| +93°F | +91°F | +84°F | ||||
| Rainfall | ||||||
| 74 mm | 85 mm | 84 mm | ||||
| Wind | ||||||
| 4 m/s | 4 m/s | 4 m/s | ||||
| Avg. water temperature | ||||||
| +60°F | +62°F | +62°F | ||||
| Humidity | ||||||
| 77% | 78% | 79% | ||||
| Air pressure | ||||||
| 1015 HPa | 1014 HPa | 1015 HPa | ||||
| Sunny days | ||||||
| 5 | 3 | 3 | ||||
| Cloudy days | ||||||
| 10 | 10 | 10 | ||||
| Rainy days | ||||||
| 16 | 17 | 17 | ||||
| Snowy days | ||||||
| 0 | 0 | 0 | ||||
August weather is still as ok as in July. It’s getting colder in August. From +70°F in the day, the average maximum temperature lowers to +68°F. Prepare for more rain. Average rainfall goes from 74 mm to 85 mm. Humidity rises from 77% to 78%. The average wind speed doesn’t change much during August, staying around 4 m/s. The days becoming less sunny, going from 5 sunny days in July to 3 in August.
September brings much the same weather, it remains ok.
Wind
The average wind speed is 4 m/s getting up to 6 m/s which is a medium breeze. You can feel it, especially getting out of the water.
The average wind speed in Cardiff is gradually decreasing during August, going from 5 m/s to 2 m/s over the course of the month.
Rain
How was the weather last August in Cardiff?
Climate Change Over the Years
The climate in Cardiff in August has not changed that much over the last 43 years.
The average temperature was the lowest in 1979 (+53°F) and the highest in 2022 (+60°F). The driest year was 2010 with only 736 mm of rainfall, and the wettest year was 2022 with 1906 mm.
FAQ
Is August a good time to visit Cardiff?
Can you sunbathe in Cardiff in August?
Can you swim in Cardiff in August?
Is Cardiff rainy in August?
Is it sunny in Cardiff in August?
Other cities in United Kingdom
Monthly weather in Cardiff
Source of the data
For this page, we’ve looked at the typical weather in Cardiff, based on historical hourly weather data from January 1, 1979, to December 31, 2023.
For past dates, we show actual recorded data at the location at that time. Forecasts are based on recorded weather during that day of the year, averaged over the total years for which we have records (unless stated otherwise). The daily temperature is the highest recorded temperature in the shadow during that day.