The Met Office has confirmed that at 12.50pm today (19 July), London Heathrow reported a temperature of 40.2°C - a record-breaking high that is set to climb as the day goes on.
Earlier today, a temperature of 39.1°C was recorded in Charlwood, Surrey, which surpasses the previous record of 38.7ºC, set in Cambridge in 2019.
🌡️ For the first time ever, 40 Celsius has provisionally been exceeded in the UK— Met Office (@metoffice) July 19, 2022
London Heathrow reported a temperature of 40.2°C at 12:50 today
📈 Temperatures are still climbing in many places, so remember to stay #WeatherAware ⚠️#heatwave #heatwave2022 pic.twitter.com/GLxcR6gjZX
Scientists at the Met Office have warned that the 40ºC figure 'could be as much as 10 times more likely in the current climate than under a natural climate unaffected by human influence'.
Professor Penelope Endersby, chief executive of the Met Office, said the public should take heat warnings as seriously as those about other significant weather events, such as snow or wind, as the extreme heat could cause thousands of excess deaths.
She told BBC Radio 4's Today programme: "Our warnings are always impact-based, so, when we put out warnings, if they're red, that means there’s a danger to life and we're expecting major infrastructure impacts, and that’s true, whether it's snow, wind, rain, and it's true of this heat warning.
"We're certainly seeing people reacting a little bit differently to the heat warnings as though they think that maybe we shouldn't be telling them to worry about heat the way we tell them to worry about storm or wind."
She added: "These temperatures are unprecedented in the UK and we're not used to dealing with them. And heat undoubtedly causes many hundreds, thousands of excess deaths in heatwaves, so people do need to take care and follow the advice we've been putting out about keeping in the shade, keeping cool, keeping hydrated, and so on."
Some schools in several counties, including Nottinghamshire and Hampshire, have confirmed they will close, while train companies urged people not to travel today or tomorrow.
Network Rail will close the East Coast Main Line between noon and 8.00pm on Tuesday for all locations between London King's Cross and York and Leeds, with passengers warned not to travel.
Sam MacDougall, operations director for Network Rail said: "Closing the line to traffic is always a last resort but it is the right thing to do to keep people safe on Tuesday given the unprecedented heatwave forecast.
"The forecast temperatures are well above those which our infrastructure is designed for, and safety must come first."
Additional contingency support for ambulance services, such as more call handlers and extra working hours, have been put in place while the chairman of the NHS Confederation said hospitals are going to be 'really, really pushed' over the next few days.
Britons are being urged to stay inside during the hottest points of the day, between 11.00am and 4.00pm, and wear sun cream, a hat, stay in the shade and keep hydrated with water.