Cardiff Weather in August
August in Cardiff brings pleasant temperatures, with daytime highs of 20°C (68°F) and nights around 14°C (57°F). Quite a bit of rainfall is expected, around 98 mm (3.9 in), so pack an umbrella.
Rainfall in Cardiff in August
Typically, you can expect about 15 days of rain this month, with 98 mm (3.9 in) on average. Expect a fairly normal spread of rainfall this month, with no particular pattern of very heavy or very persistent showers.
Temperature in Cardiff in August
If you're visiting Cardiff in August, expect perfect temperatures with highs of 20°C (68°F) and overnight lows of 14°C (57°F). August is known for being in the summer season. Conditions are often most pleasant around the middle of the day. With overnight lows of 14°C (57°F), evenings can feel noticeably cooler than the daytime. An extra layer is a good idea, though the cool air makes for a good night's sleep. On average, it has the peak temperatures of the year.
Sunshine in Cardiff in August
The area experiences a moderate amount of sunshine, with approximately 184 hours of sunlight expected. This means a decent mix of sun and overcast.
Wind Speed in Cardiff in August
August sees wind speeds averaging 4 m/s (8 knots). You'll experience variable conditions with moderate winds that create small waves on water and keep branches moving. Conditions range from light winds to moderate breezes throughout the month.
Average water temperature in August
With water at 16°C (61°F), it's on the cooler side. Keen swimmers won't be put off, but those who prefer warm water may find it less enjoyable.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 August
Min Temperature
14°C (57°F)
Max Temperature
20°C (68°F)
Water Temperature
16°C (61°F)
Chance of Rain
51%
Precipitation
98 mm (3.9 in)
Rainy days
15 days
Humidity
78%
Windspeed
4 m/s (8 knots)
Sunshine
184 hours
Percentage Sunshine
42%
Daily Historical Temperatures
50-year average (1976-2025)
Based on our historical records, temperatures in Cardiff typically stay consistent throughout August, with daily highs averaging around 20°C (68°F). Nights are cool, with lows typically ranging from 12°C (54°F) to 14°C (57°F).
Average temperatures in August
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 August
Historical weather for Cardiff in August
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 August
Based on weather observations in Cardiff between 1976 and 2025, these are the recorded extremes during August.
- On August 3, 1990, temperatures climbed to 33°C (91°F), marking the warmest August day on record.
- The lowest daytime temperature in August was 14°C (57°F), recorded on August 3, 1986.
- Nighttime temperatures dropped to 6°C (43°F) on August 24, 1980, marking the coldest August night on record.
- Peak precipitation in August occurred on August 2, 2016, when 48 mm (1.9 in) of precipitation was measured.
Best Places in the United Kingdom in August
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 August →
perfect weather
pleasant
tolerable
unpleasant
poor
What to Wear in Cardiff in August
For Cardiff in August, you'll want flexible clothing. It's wise to pack cotton shirts, comfortable shorts, and a pair of jeans for cooler evenings. A light sweater or jacket is useful for air-conditioned spaces (like buses) or unexpected cool moments. High rain levels are expected, so pack waterproof gear and an umbrella or poncho. The water temperature sits at about 16°C (61°F), which is too chilly for most people to enjoy swimming. Leave the swimsuit at home unless you love cold water. It won't hurt to bring your sunglasses along, as you'll see some sunny periods.What To Do in Cardiff in August
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.
