People in the UK have flocked to beaches with temperatures approaching 36C on Saturday as the mini-heatwave continues. Friday was the hottest August day in 17 years, with 36.4C recorded at Heathrow and Kew Gardens in London, and temperatures are expected to remain high until the middle of next week. The Met Office said temperatures reached 34.5C at Frittenden in Kent on Saturday, and that although there was some cloud south-east England could again peak at 36C. Crowds of people headed for the coast, with images showing packed beaches, traffic jams and full car parks. Much of Bournemouth’s coast was deemed unsafe on Saturday by the local authority and people were told to avoid 19 of its 24 beaches because “safe social distancing is not possible”. Some beachgoers complained about larger groups arriving later in the day and not respecting physical distancing, but others were unconcerned. Brighton beach was seen packed with sunseekers and many were also pictured in Weymouth, Anglesea, Lyme Regis and elsewhere. In Sussex, police turned away cars from the beach area as the car park was full by 10am. Parts of the UK could have record overnight temperatures this weekend, with London and the south-east experiencing unusually hot weather over the past few days. The Met Office has said more records may be matched or broken in the coming days with some extremely hot and sticky nights on the way. Temperatures in parts of south-east England will remain above 20C, potentially reaching the overnight record of 23.9C set in Brighton on 3 August 1990. The Met Office has issued a level-three health warning for the south and south-east, meaning the public should look out for others, particularly children, older people and those in poor health. Ishani Kar-Purkayastha, a Public Health England consultant, said: “This summer, many of us are spending more time at home due to Covid-19. A lot of homes can overheat, so it’s important we continue to check on older people and those with underlying health conditions, particularly if they’re living alone and may be socially isolated.” Dan Harris, the Met Office’s deputy chief meteorologist, also said, however, that thunderstorms were on the way and that some places may receive up to 80mm of rain in a few hours. “We’ve issued a broad thunderstorm warning for Monday and Tuesday for all parts of the UK, since although the ingredients are there, it’s just too early to pinpoint the details of exactly where and when thunderstorms will occur,” he said. “As such, we will be monitoring the developing signals closely and I urge people to keep a close eye on Met Office warnings and forecasts over the coming days.” The climate crisis has made UK heatwaves 30 times more likely and extreme temperatures led to 3,400 early deaths between 2016-19. The government’s official advisory body, the Committee on Climate Change, said on 25 June that “the UK is poorly prepared for the very serious impacts of climate change, including … overheating”. The hottest August day on record is 38.5C, recorded in Faversham on 10 August 2003. The UK’s highest temperature, of 38.7C, was recorded at Cambridge Botanic Garden on 25 July last year. South East Water warned that people could be without tap water unless usage was cut as it called on people to “put away the hose pipes, garden sprinklers and garden water toys” to ensure there was enough for everyone to drink.