Weather Forecast August 2024 Cornwall. Cornwall's famous music and surf festival is about to begin. Get the monthly weather forecast for st ives, cornwall, united kingdom, including daily high/low, historical averages, to help you plan ahead.

Expect 19°c daytime maximum temperatures in the shade with on average 6 hours of sunshine per day in cornwall in. The met office’s uk weather forecast for august shows heatwave conditions ‘subsiding’, with the country facing a ‘cooler airmass’ and ‘rain’.