The warm weather will be concentrated across East Anglia and south-east England on Monday and Tuesday before spreading across the Midlands, east Wales and north England by the weekend.
On Monday we are likely to reach 26C, by Wednesday the heat becomes much more widespread with highs of 28C, and by the weekend the hot spots surge somewhere between 30 and 33C.
Meanwhile, it will become warmer in Northern Ireland and Scotland later in the week, but it will be more comfortable here with temperatures mostly in the low 20s.