Britons asked to stay indoor as UK faces hottest day ever

People in the UK are being advised to stay indoors and avoid non-essential travel as the country faces its hottest day on Monday, with temperatures set to edge towards the 40-degree Celsius mark for the first time since records began.

A national emergency is in place by the UK Health Security Agency (UKHSA) and the Meteorological (Met) Office has issued its first-ever red alert for extreme heat, warning of danger to life from the extreme heat. The heatwave is set to peak on Tuesday before some rain forecast for Wednesday.

We may well see the hottest day in UK history," said Professor Penny Endersby, chief executive of the Met Office.

"Tomorrow [Tuesday] there's a higher chance of 40C and above, possible numbers 41 are on the cards, some 43 in some models, but we're hoping it won't be as hot as that," she told the BBC.

She urged people to take the warnings seriously as they would any forecast of storm or other harsh weather.

"These temperatures are unprecedented and we're not used to dealing with them heat causes many hundreds or thousands excess deaths, so people need to follow the advice of keeping the shade, keeping cool and hydrated," she added.

The highest temperature ever recorded in Britain is 38.7 C (101.7 F), a record set in 2019. People are being warned of major disruption to journeys by train and car. Downing Street said railway speed restrictions may be needed "on some parts of the network... to manage the hot weather and to avoid any potential damage .

Very hot temperatures can affect rails, overhead power lines and signalling equipment, as well as "bend and buckle" tracks.

Network Rail, which runs the country's railway networks, warned that journeys will take significantly longer and delays are likely. It, along with Transport for London (TfL), is strongly encouraging customers not to travel on Monday and Tuesday.

"Due to the exceptionally hot weather that is expected... customers should only use London's transport network for essential journeys. If customers do need to travel, they should check before they travel as we are expecting there to be some impact to Tube and rail services," said TFL chief operating officer Andy Lord.

London Mayor Sadiq Khan said he supports calls for some industries to adapt working hours to make sure employees aren't in danger in the hottest temperatures.

New buildings now have cooling systems, rely on renewable energy and are insulated, he said.

Some schools have also decided to cancel planned sports days or shut down, with others keeping some staff on site and allowing children to wear their cooler sports uniforms if their parents are unable to find childcare at short notice. The majority of UK schools are set to break up for the summer holidays later in the week and might accelerate that date.