Britain was colder than the Arctic Circle on one of the wettest bank holidays in recent years.
Forecasters said the "unseasonably cold" temperatures generally ranged between 7C and 10C, when they would normally be around 17C at this time of year.
Thousands of homes were left without electricity after high winds brought down power lines in the east of England.
St Catherine’s Point on the Isle of Wight saw the worst of the rain, with 52mm.
Meanwhile, play in the England versus West Indies cricket test match in Leeds was stopped by hail.
Forecasters are warning that the UK is in for an "unsettled" week, but temperatures are expected to pick up and could hit an above-average 22C by the weekend.
In Edinburgh, a Met Office spokesman said temperatures today would remain around 10C or 11C although tomorrow should be the "best day of the week" at 16C with some sunshine.
He added that the rest of the week would be affected by further rain, although it is set to be dry on Saturday.