A mother and her seven-year-old son were among three people who died on Saturday as strong winds and rain battered parts of Britain’s coast.

The 37-year-old woman and the boy were among five people pulled from the sea after they got into difficulty while playing at Aberdeen beach. They later died in hospital. Another boy, aged 13, was still being treated in hospital along with a 25-year-old woman and a man aged 28. They had yet to be named.

Chf Insp Stewart Mackie, of Police Scotland, said: “This is a very tragic incident which has resulted in a woman and young boy sadly losing their lives. It will undoubtedly bring shock and sadness to the entire city of Aberdeen and farther afield. Given the recent weather we’d urge members of the public to take care, especially when near coastal or beach areas.”

The third victim was a windsurfer, in his 60s, who died in hospital in Colchester shortly after being rescued by the crew of a lifeboat from the sea off West Mersea, in Essex. A police spokesman said they were trying to establish the events leading up to his death. Mersea Island, which is situated where the Blackwater estuary widens out into the North Sea, has become a hub for wind and kitesurfers in recent years.

The Met Office issued a yellow “high winds” alert for East Anglia’s coast on Sunday, warning that winds could gust at more than 50mph.

Earlier, on Friday, tragedy struck a family of five from Surrey who were on a trip to Fistral Beach in north-west Cornwall. The Maritime and Coastguard Agency said a man was swept out to sea with his wife and two-year-old daughter, and he later died in hospital.

Lifeguards reached the man and his wife, said to be in their 30s, and the girl, amid treacherous conditions with 13ft waves. Two other children in the family managed to scramble back on to the rocks.

James Instance, of Falmouth coastguard, told the BBC: “We went through a 24-hour period where the waves went from half a metre to three to four metres. You are probably looking at 10ft breaking waves in this area.”

Gales hit Wales and southern and central England, bringing a very unsettled and blustery end to the recent sunny spell. The unseasonal weather caused summer events to be cancelled at short notice and the Environment Agency called for walkers who were planning a coastal stroll this weekend to avoid taking photographs in dangerous spots.

Craig Woolhouse, Environment Agency flood risk manager, said: “We urge people to stay safe on the coast and warn wave-watchers against the unnecessary dangers of taking ‘storm selfies’.”

Temperatures are expected to drop from a high of 28C earlier this week to as low as 20C or even the high teens in many parts over the weekend. Warmer weather should return from the middle of next week, just in time for the August bank holiday.