Parts of Norfolk could reach 20C next week as forecasters predict record-breaking temperatures for the time of year.
Tuesday is expected to be the warmest day before temperatures drop off again heading into the Easter weekend.
The warm weather in the early part of the week will coincide with lockdown measures easing and people being able to meet family and friends in groups of up to six or two households.
Across the country, parts of the UK will be hotter than Saint Tropez and Ibiza as the mercury could rise to 24C in south-east England by mid-week.
It would be only the second day in March that the temperature has reached this high in records going back to 1884. The maximum temperature recorded in March was 25.6C (78F), on March 29 1968 at Mepal in Cambridgeshire.
The warm spell will come after a mixed weekend.
In Norfolk, Saturday will get off to a bright chilly start with temperatures hovering around 5C. As the day develops, temperatures are predicted to reach highs of 11C with sunny spells and breezy conditions, which will be stronger on the coast.
Sunday is expected to be overcast with the chance of showers first thing and highs of 14C by mid-afternoon.
Greg Dewhurst, a Met Office forecaster, told the PA news agency: "The weekend should be a mixed bag for many with a big north-south split.
"Southern regions will certainly see the warmer, sunnier conditions with a band of rain moving through Northern Ireland on Saturday afternoon before heading into parts of northern England and Scotland.
"Saturday will certainly be the better of the two days, with Sunday becoming windy and grey for most."
Mr Dewhurst said southerly winds along with an area of high pressure would move in on Monday.
He added: "Into next week large swathes of southern England and Wales will be dry with warmer temperatures than expected for this time of year, the average for March being 11-12C.
"The mercury could reach a high of around 18C on Monday, with Tuesday seeing highs of 24C (75.2F).
"Much of the UK will remain dry and bright until Wednesday, while parts of Scotland will see some heavy showers."
Conditions are expected to change again from the middle of the week, the Met Office said, with cold air from the north bringing another dip in temperatures for Easter weekend.
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