Britain could see its highest UV levels ever recorded on Thursday as the UK’s heatwave continues – before thunderstorms and torrential rain bring an abrupt end to the baking hot weather.
After the UK sweltered on its hottest day of the year so far on Wednesday, the record is expected to be beaten once again later when temperatures are expected to reach as high as 34C (93.2F).
The heatwave has seen people flock to beaches and beauty spots in huge numbers despite social distancing measures remaining in place.
People in England and Wales have been urged to avoid being outside at around midday on Thursday after the Met Office predicted UV radiation from the sun to reach a “rare” level eight – meaning “very high”.
According to the Met Office’s website, the UV index “does not exceed eight in the UK” – but level nine is predicted in parts of the South West.
The aim of the UV index is to urge people to change their behaviour to protect themselves against the risks of skin cancer and skin damage.
Dr Michaela Hegglin, a professor in atmospheric chemistry at the University of Reading, said some of the “highest UV levels ever recorded” in Britain could be seen on Thursday.
She said: “We are at the summer solstice, when the sun is almost directly overhead at one o’clock.
“UV levels this high are rare in the UK, so people with light skin should be very careful to avoid getting burnt.
“While UV is important for getting vitamin D and keeping us healthy, too much of it can cause skin cancer or eye cataracts.”
West London is forecast to see temperatures peak between 32C (89.6F) and 33C (91.4F) on Thursday, while parts of Wales could see the mercury rise to 34C (93.2F).
Should that happen, it would be the hottest June on record in Wales, surpassing the previous peak of 33.7C (92.7F) on June 18 2000.
But weather warnings for thunderstorms have been issued across the west of Britain and Northern Ireland from 4pm, with heavy rain, lightning and hail expected to bring a risk of flooding.
Between 30mm to 40mm (1.6ins) of rain could fall in less than two hours.
The storms are expected to continue on Friday, with a weather warning for thunderstorms in place for the whole of the UK.
Areas hit by the storms could experience “torrential downpours” with between 30mm to 50mm (2ins) of rain falling in an hour.
Want to know what the #weather #4cast is 4 tomorrow?— Met Office (@metoffice) June 24, 2020
It is shaping up to be another #hot 🌡️ day for many of us with plenty of strong #sunshine ☀️.
Watch out for a few #thunderstorms ⛈️ in places though.
Here are the details 👇#UKHeatwave pic.twitter.com/OCVSGVav4Z
Wednesday was officially recorded as the hottest day of the year so far, with 32.6C (90.7F) at London’s Heathrow Airport.
During the sweltering conditions, Thames Valley Police said a body had been found on Wednesday in the search for a man missing in the River Thames.
The man in his 30s was discovered after reports he got into difficulty while swimming in a stretch of water called Lulle Brook in Cookham, Berkshire, on Tuesday evening.