In Ripon, temperatures will hit a dizzying 19C on Sunday, which will also be the case in Sheffield and Hull.
Scarborough will match the 18C in Leeds, so a day at the beach might be in order.
Forecasters predict much of the country will be bathed in sustained sunshine, ensuring April averages are exceeded while millions enjoy time off.
By Sunday, temperatures could jump to 19C in the North of England - and 23C in South East England.
Across the UK, the thermometer should reach 17C, apart from the north east of Scotland, which seems set to remain cloudy for much of the weekend.
Sunseekers can start slipping on the shades on Friday, however, with clear skies prevailing over much of the UK, the Met Office said.
Southern and eastern parts of England and Wales will revel in the best of today's weather, which is predicted to reach up to 17C, a forecaster added.
As the weekend begins, the heat is anticipated to start creeping up throughout Saturday, peaking at 18C or 19C across north-west Wales and in central parts of England.
Met Office forecaster Greg Dewhurst said: "It is likely on Sunday we will see further sunshine for many parts of the UK.
"In the sunshine across England and Wales we will see temperatures above average for this time of year, above 18C or 19C.
"It will be a lovely weekend for much of England and Wales, but in Northern Ireland and Scotland it will turn a bit cloudier."
The warm weekend will dissolve back to average temperatures on Monday morning, he added.
April's agreeable outlook follows the mildest March on record last month, when the month welcoming in the spring recorded its fifth-equal warmest outing since 1910.