Mild
Average highs are around 20°C, so days are mild rather than hot.
Weather Guide
Cardiff, Wales, United Kingdom Average Monthly Weather
Weather score26Poor annual avg
Best months: July, August, June
Across the year, average daytime temperatures are around 14°C, sunshine averages 4.1h per day, and rainfall totals about 1002mm. Sea temperatures average 12°C across the year.
Annual weather
Annual averages
Temp
14°C
Rain
1002mm
Annual total
Sun
4.1h
Sea
12°C
Weather score
26
Poor avg
Seasonal climate calendar
TemperatureTemp
RainRain
SunSun
SwimSwim
Weather scoreWeather score
Trip feel
Showers
Rainfall averages 81mm, so some wet days are possible.
Some sun
Sunshine averages 6h per day, enough for a balanced month.
Cool sea
Sea temperatures average 18°C, so the water can feel cool.
Map
Weather map
Compare Cardiff, Wales, United Kingdom with nearby places by weather score, rain, sun, temperature, and swim conditions.
Temperature
August20°C average high
August is one of Cardiff's warmest months, with daytime heat above the yearly average.
Warmest monthsJune to September
This stretch sets the upper range for average daytime heat.
Rain
August81mm average rain
August sits near Cardiff's yearly rainfall average, so rain is a normal planning factor rather than an outlier.
Driest monthsFebruary to August
This is the drier part of the year, when outdoor plans usually need less weather flexibility.
Sun
August6 hours average sun
August is brighter than Cardiff's yearly average, though the strongest sunshine usually sits closer to the peak months.
Brightest monthsMay to August
This stretch has the strongest sunshine in the monthly averages.
Sea temperature
August18°C average sea
August is one of Cardiff's warmest sea months, when swimming comfort is usually strongest.
Warmest seaJuly to September
Sea temperatures are usually near 17°C in this stretch, so swimming comfort is at its strongest.
Weather score
August43 weather score
August is one of Cardiff's best weather-score months, combining the strongest overall balance in the yearly averages.
Best weather monthsJune to August
These months have the strongest weather score in the monthly averages.
