Wednesday was the hottest day of the year so far, with 30.3C (86.5F) recorded at Heathrow, the Met Office has confirmed. The scorching temperatures, which were concentrated in the south of England, hit as thousands descended upon Somerset to attend the Glastonbury music festival. Some festivalgoers deployed umbrellas to shield themselves from the sun while others poured bottles of water on their heads to cool off. Kathryn Chalk, a Met Office meteorologist, said 30.3C was “the highest maximum temperature this year. Yesterday we got to 30C and that was the first time we reached 30C since 10 September last year.” In parts of the north of England temperatures could fail to go beyond 24C, while in Aberdeen a peak of 18C was forecast. People flocked to beaches to take advantage of the sunny weather. Brighton was full of people sunbathing on the pebbly beach and in Blackpool sun-seekers unfolded their deck chairs. The NHS said visits to its online heat exhaustion advice page had soared in the past 48 hours. Figures from NHS England show that on 24 and 25 June there were 28,116 visits to the heat exhaustion page, compared with 13,598 on 22 and 23 June – a 107% increase. The heat is likely to subside as soon as Thursday, when temperatures are forecast to fall to the low to mid-20s. Chalk said the weather would become wetter and cooler through Thursday and into Friday. “We’ve got a low pressure system coming into the north-west,” she said. “That’s going to bring windy conditions and some rain and showers – so make the most of the heat today and tomorrow. “As we go into Friday we will see bright and breezy conditions in the north, while showers are going to be focused across Scotland.” She said the weather would remain relatively warm, with highs of around 24-25C through the weekend.