The Met Office says two regions could reach 29C on Sunday, while the northwest faces heavy rain and winds gusting above 50mph. The sharp contrast will develop as an area of low pressure moves to the north and west of the UK, drawing warmer air northwards and bringing rain and strong gusts to some areas.
Saturday settled before overnight shift
Saturday is expected to be largely settled, with many areas enjoying dry weather, sunshine and light winds. Southern areas could reach 23C or 24C, while temperatures further north are expected to remain in the mid to high teens, the forecaster says.
But the weather will shift significantly overnight as the Atlantic low pressure system approaches. Southerly winds will pull warm air from continental Europe towards England and Wales, pushing temperatures into the mid-20s widely across the two nations.
Sunday split: warmth in the south, rain in the northwest
Central and eastern England could climb as high as 28C or 29C on Sunday, with a low chance of 30C if cloud remains limited. At the same time, the northwest will be hit by a much wetter and windier spell.
Bands of heavy rain and showery rain are expected to move into these areas during the early hours of Sunday, with rain continuing through the day across Northern Ireland, the Highlands, southwestern Scotland and parts of Cumbria, including the Lake District. The highest rainfall totals could reach around 50mm to 60mm, although there remains some uncertainty over exactly where the wettest conditions will occur.
Gale-force winds and cooler conditions ahead
Winds will also strengthen around the low-pressure system, with gale-force winds possible across northwestern parts of the UK. Gusts could exceed 50mph for a time, potentially bringing some disruption.
For much of England and Wales, however, Sunday will be a very different story, with most places remaining dry and temperatures soaring before the warmth proves short-lived, the Met Office says. Cooler conditions are expected to return next week.
In its outlook for Sunday to Tuesday, the forecaster says: "Rain spreads southeast, heaviest in western Scotland. Brighter conditions follow with showers, some heavy and thundery. Windy at times. Very warm on Sunday, then turning cooler for the coming days."
