Sunday could be the UK’s hottest day ever recorded
There could be a danger to life or potential serious illness
There is a 30% chance that Sunday will be the hottest day ever recorded in the UK.
The rare warning states there could be a danger to life or potential serious illness as a result of the scorching temperatures.
Other issues could include road closures and delays or cancellations to rail and air travel.
The warning has now been updated to include Monday
The rare “amber” warning for exceptionally high temperatures, posing a potential risk to life, was first issued to cover Sunday and has now been updated to include the whole of Monday.
The Amber warning, which has been issued for Sunday (17 July) and Monday (18 July), highlights likely adverse health effects for the public.
The Amber Warning comes at the end of a week when the UK will see widely-above average temperatures, with a Level 3 UK Health Security Agency Heat Health Alert in place for southeastern areas this week, and a Level 2 alert for much of the rest of England.
Sunday could be the hottest day on record
Temperatures are predicted to soar into the 30s, with a 30% chance of seeing the hottest day on record for the UK, beating the existing high of 38.7C in Cambridge in 2019.
Simon Partridge told the PA news agency says "Parts of south-east England could exceed 35C on Sunday.
"At the moment, we are looking at a 30% chance of seeing the hottest temperature recorded in the UK."
The weather warning is being enforced across the East Midlands, east of England, London, South East, North East, North West, South West, Wales, West Midlands and Yorkshire and Humber.
The whole of England is likely to be affected
The whole of England is largely expected to experience sunny days with some cloud over the next week to match the temperatures of mid to high 20s.
It will cool off a little on Thursday and Friday, with the North West and North East of England predicted to have some rain.
Temperatures are expected be over 35C in the South East on Sunday, and overnight temperatures will also be very warm.
Parts of Wales will see temperatures of more than 32C on Sunday and Monday.
Northern Ireland and Scotland – away from far northern areas – will still see warm sunny days, and while temperatures will not be as high as elsewhere, they will reach the high 20Cs, the forecaster said.
Speed restrictions are likely to be in place
Network Rail has warned speed restrictions are likely to be in place this week on some parts of the network most affected by the hot weather.
Fire services have urged people to have picnics instead of barbecues during the warm weather after a spate of grass fires.
The AA Driving School and RAC meanwhile said motorists should carry water with them, start their journeys earlier in the day, plan their routes and check their vehicles before setting off.
Hampshire County Council also said it was preparing to deploy gritters to protect cars against melting roads.
The Met Office says the mercury is predicted to rise to 30C in London, Chelmsford, in Essex, and Sudbury, in Suffolk, on Tuesday while the rest of England is expected to see temperatures soar to the late 20s.
The UK must adapt to a future of more intense heatwaves, with new homes built to cope with higher temperatures, more green areas in cities, and measures such as external shading and insulation fitted to existing properties, experts said.
Scientists warn that current heatwaves have been made hotter, longer and more frequent by climate change.
Households are being urged to save water as the temperatures push up demand after months of dry weather in some areas.
Water companies say they are not yet planning to bring in restrictions such as hosepipe bans, but some are warning that groundwater and reservoir supplies are lower than average following low rainfall this year.