Cardiff Weather in May
May in Cardiff sees daytime temperatures around 16°C (61°F) and lows of 9°C (48°F) at night. With around 79 mm (3.1 in) of rainfall expected, it's worth packing a rain jacket.
Rainfall in Cardiff in May
Records from the past 30 years suggest around 15 days of rain, with 79 mm (3.1 in) average for the month. Neither particularly heavy nor particularly frequent, the rain this month is about average. A light jacket should be enough on most wet days.
Temperature in Cardiff in May
Daytime temperatures in Cardiff reach 16°C (61°F) in May, dropping to 9°C (48°F) at night. Conditions are often most pleasant around the middle of the day. At 9°C (48°F) overnight, it gets properly cold after dark. On the bright side, cold nights tend to make for excellent sleeping conditions.
Sunshine in Cardiff in May
Expect sunny days throughout the month, with an estimated 197 hours of sunshine. This makes it a pleasant time to visit Cardiff.
Wind Speed in Cardiff in May
Wind speeds average 4 m/s (8 knots) during May. At this speed, expect moderate winds that can raise dust and move small branches. Since this is an average, some days have gentle light winds while others experience stronger breezes that are quite noticeable.
Average water temperature in May
At 11°C (52°F), the water is very cold. Most people find it too uncomfortable for anything beyond a brief wade.If your ideal day consists of dry skies and pleasant temperatures, July and August typically offer the best circumstances 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 May
Min Temperature
9°C (48°F)
Max Temperature
16°C (61°F)
Water Temperature
11°C (52°F)
Chance of Rain
51%
Precipitation
79 mm (3.1 in)
Rainy days
15 days
Humidity
74%
Windspeed
4 m/s (8 knots)
Sunshine
197 hours
Percentage Sunshine
41%
Daily Historical Temperatures
50-year average (1976-2025)
Based on our historical records, temperatures in Cardiff typically stay consistent throughout May, with daily highs averaging around 16°C (61°F). Nights are cool, with lows typically ranging from 7°C (45°F) to 10°C (50°F).
Average temperatures in May
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 May
Historical weather for Cardiff in May
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 May
According to our 49 years of weather records for Cardiff, the following extremes were recorded between 1976 and 2025.
- Cardiff recorded its highest May temperature of 26°C (79°F) on May 24, 1989.
- The coldest May day was on May 1, 1979, with a maximum of 6°C (43°F).
- The lowest overnight temperature recorded in May was -1°C (30°F) (May 5, 1982).
- The heaviest May precipitation occurred on May 10, 1992, when 46 mm (1.8 in) of precipitation fell.
Best Places in the United Kingdom in May
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 May →
perfect weather
pleasant
tolerable
unpleasant
poor
What to Wear in Cardiff in May
Pack for changing conditions in Cardiff in May. Bring a mix of short and long sleeves, a warm layer like a hoodie or light jacket, and comfortable pants. The key is being able to add or remove layers as the days goes by. Rain gear is recommended, you can expect wet weather on multiple days. With water temperatures around 11°C (52°F), the water is quite cold for swimming. You can skip the swimwear unless you're particularly tough. And with plenty of sunshine hours, don’t forget sunglasses, sunscreen, and maybe a sun hat.What To Do in Cardiff in May
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.
