Up to nine counties saw record breaking temperatures today amid a 'historic' 35C bank holiday heatwave in Britain. Tens of thousands of Britons flocked to the coast and beauty spots to bask in the blistering heat despite official government guidance to stay out of the sun during the hottest times of the day. A searing 34.8C was recorded in Kew Gardens, south-west London, exceeding the previous hottest May day of 32.8C in 1944 - as well as the bank holiday record of 33.3C in August 2019.The Met Office said the 34.8C heat is 'exceptional in the UK even in mid summer, let alone in May'. Wales saw its hottest ever temperature in May on Monday evening, with 32.2C recorded at Hawarden Airport in Flinshire. The previous record of 30.6C in Newport stood for 82 years.Up to nine counties, including Greater London, Surrey, Norfolk and Oxfordshire, saw temperatures soar above 32C - and the Met Office forecasts the mercury could yet climb to 35C today and tomorrow. Amber and yellow health alerts remain in place across England, as temperatures continue to soar on what the Met Office has described as an 'unprecedented' heatwave for this time of year.The warnings came as a man died on the beach in Hastings, East Sussex, following a 'medical incident', and a 15-year-old boy drowned at Swanholme Lakes in Lincoln on Sunday.