Weather in Cardiff in May 2025
Average weather
Average temperature in Cardiff in May
Going from a maximum of +21°C during the day to a minimum of +5°C during the night, the temperature in May averages around +18°C.
The average maximum temperature goes up 0% by the end of the month, compared with the beginning of the month, from +19°C to +19°C.
Is Cardiff warm or cold in May?
Cardiff is typically mild in May.
Maximum temperatures go up compared to the previous month from +13°C to +16°C. The minimum temperature also goes up from +6°C to +9°C.
Pack a light jacket as it will be warm in the day and cool in the evenings.
Take a look at how May is compared to other months in Cardiff:
Water temperature in Cardiff in May
Water in Cardiff in May is Cold. It varies from +10°C to +13°C, with an average of +11°C. This is almost similar to the air temperature, which averages +16°C.
In May, water temperatures are average relative to the rest of the year:
Can you swim in Cardiff in May?
Climate in Cardiff in May
| April | May | June | ||||
|---|---|---|---|---|---|---|
| Avg. temperature | ||||||
| +13°C | +16°C | +19°C | ||||
| Min. temperature | ||||||
| -2°C | 0°C | +3°C | ||||
| Max. temperature | ||||||
| +25°C | +27°C | +30°C | ||||
| Rainfall | ||||||
| 63 mm | 72 mm | 74 mm | ||||
| Wind | ||||||
| 4 m/s | 4 m/s | 4 m/s | ||||
| Avg. water temperature | ||||||
| +10°C | +11°C | +14°C | ||||
| Humidity | ||||||
| 76% | 76% | 77% | ||||
| Air pressure | ||||||
| 1014 HPa | 1014 HPa | 1015 HPa | ||||
| Sunny days | ||||||
| 5 | 5 | 4 | ||||
| Cloudy days | ||||||
| 10 | 10 | 10 | ||||
| Rainy days | ||||||
| 15 | 15 | 15 | ||||
| Snowy days | ||||||
| 0 | 0 | 0 | ||||
May weather is still as ok as in April. It’s getting warmer as May arrives. The average maximum temperature goes up from +13°C to +16°C during the day. Prepare for more rain. Average rainfall goes from 63 mm to 72 mm. Humidity levels don’t change as the month goes on, averaging around 76%. The average wind speed doesn’t change much during May, staying around 4 m/s. The amount of sunny days stay about the same, averaging 5 sunny days during the month.
June brings much the same weather, it remains ok.
Wind
The average wind speed is 4 m/s getting up to 7 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 increasing during May, going from 4 m/s to 6 m/s over the course of the month.
Rain
How was the weather last May in Cardiff?
Climate Change over Years
The climate in Cardiff in May has not changed much over the last 43 years.
The average temperature was the lowest in 1979 (+12°C) and the highest in 2022 (+16°C). The driest year was 2010 with only 736 mm of rainfall, and the wettest year was 2022 with 1906 mm.
FAQ
Is May a good time to visit Cardiff?
Can you sunbathe in Cardiff in May?
Can you swim in Cardiff in May?
Is Cardiff rainy in May?
Is it sunny in Cardiff in May?
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.