Organiser Dai Thomas dressed as Father Christmas to greet participants in the annual charity swim at Porthcawl, South Wales. More people are out than in the summer, he said.
More than 600 people braved the cold to take part in the annual Christmas Day swim at Coney Beach in Portcawl, South Wales. Thousands of spectators turned out to watch.
The Serpentine Swimming Club's race in Hyde Park has taken place every Christmas Day since 1864. Sally Kelly, 33, celebrates in the lake after becoming the first woman to win.
Swimmers in south west London took advantage of a more comfortable environment. Hundreds took an early morning dip in the heated waters of Hampton open air pool.
Hampton pool maintains its temperature at 28C. The Bristol Channel and English Channel were among the other venues for more challenging festive swims.