Heavy rain will push across southeast England this morning, with showers also possible in the north and Scotland.
The Met Office said it will be drier and brighter in the west of the country, but temperatures will be fresh across the board.
Tonight the daytime showers will fade – but cloud and rain will arrive in western England and Wales tomorrow morning.
On Friday winds will blow cloud across the UK, with outbreaks of mostly lightly rain – but heavy showers are forecast for Scotland.
But this weekend will see sunshine and summery temperatures return to much of Britain.
Met Office forecasters said the mercury could reach 23C in London and parts of Essex and Kent at 4pm on Saturday – a promising start to July.
Elsewhere in the country temperatures will range from 22C in Brighton to 13C in Stornoway.
Despite the pleasant temperatures, there is still likely to be rain with brisk winds across northern England.
It will be mostly dry on Sunday and Monday with sunny spells – and scattered showers in the north west.
Temperatures will settle around the early July average, with the balmy heat of June a fading memory.