On Thursday temperatures are expected to rise to around 25-28C across the Midlands, East Anglia and south-east England, where there’ll also be some sunshine.
Elsewhere it will stay fairly cloudy with some rain, easing to showers, with temperatures around 17 to 24C, closer to the average for mid-June.
There will be another bout of wet weather on Friday in Northern Ireland, Scotland, northern and western areas of England and Wales.
It will then turn drier and sunnier for all parts over the weekend with some light winds. Temperatures in these areas will rise a little over the coming days, they will remain at the modest level of 19 to 26C.
The heat across southern and eastern areas of England is expected to build further on Friday with temperatures of 27 to 31C expected.
While less hot on Saturday, by Sunday and Monday temperatures could return to the high twenties and up to 31 or even 32C.
By Monday there could be some big thunderstorms developing across England and Wales.
With the heat persisting into Tuesday across south-eastern areas, some locations may enter official heatwave conditions with temperatures above 27C or 28C for three consecutive days.
The heatwave threshold varies in each county, but it sits between 25C across Scotland, Northern Ireland, Wales and parts of the south-west of England, and 28C in London.