Crowds flocked to the beaches to soak up the sunshine as temperatures hit almost 23C across parts of England.
Photographs show hundreds of people packed onto Bournemouth beach in Dorset on Saturday, while in the north kayakers took to Derwentwater in the Lake District.
A man was taken to hospital after falling down the side of a slipway near the Beacon in Redcar, North Yorkshire, at around 1.20pm.
The Royal National Lifeboat Institute (RNLI) in Redcar said the man suffered head and potential spinal injuries.
Temperatures hit highs of 22.8C at Wisley in Surrey at 3pm, 22.7C in Hull and 22.6C at St James’ Park in central London.
The mercury is forecast to rise even higher on Sunday, with 24C expected in London and 21C in Newcastle.
However, Met Office meteorologist Sarah Kent said: “It’s not going to be wall-to-wall sunshine tomorrow, which will probably disappoint quite a few.
“First thing on Sunday morning there will be quite a lot of cloud across central parts of England, eastern Wales, and down to the South West.
“And in that zone there will be outbreaks of rain, with the odd heavier burst of rain in the South West.”
There will be a mixture of bright spells elsewhere throughout the morning, but the weather will begin to turn later in the day with a risk of widespread showers.
Northern Ireland and northern Scotland will see the best of the weather on Sunday, with only the “odd rogue shower” forecast during the day, Ms Kent said.
Showers and cloudy skies are forecast for northern England on Monday, turning to sunshine, with thunder and heavy showers by mid-afternoon in central and eastern areas.
Ms Kent said weather warnings may be put in place depending on the severity of the showers.
Despite the unsettled weather, temperatures are forecast to hit 25C in London and up to 21C in northern Scotland.