Britain has boiled on its hottest ever June day after temperatures reached a blistering 36.1C.

The 50-year record was first broken this afternoon in Charlwood, Surrey, when the mercury reached 35.7C, surpassing the previous record of 35.6C set in 1976 during a ten-week heatwave, the Met Office said.

But the June heat record has now been pushed even higher, with 36.1C recorded in Gosport, Hampshire.

Forecasters had predicted the June record would be ‘absolutely smashed’ – as Britain and Europe remain trapped in a heat dome. Temperatures are set to soar even higher this week to a possible 40C.

Earlier, the record-breaking temperatures caused a climate conference to be cancelled and the All England Club was forced to suspend Wimbledon qualifying after the automated line-calling system suffered a heat-related meltdown.

Players were taken off court after it was decided chair umpires could not make line calls in the absence of the electronic system and, unlike in the main Championships, there are no reserve line judges available during qualifying.

Meanwhile, a 15-year-old boy has gone missing while swimming in a lake in Hampshire.

The teenager was last seen at Testwood Lakes Nature Reserve near Totton, at around 1.30pm – with rescue teams and marine units currently scouring the water.

Elsewhere, the King felt the heat as he met guests at the London Climate Action Week reception and had to be fanned by one of his top aides.

Charles joined delegates from politics, science, business and international climate diplomacy for the reception at St James’s Palace, where temperatures were stifling.

 

Master of the Household, retired Vice Admiral Tony Johnstone-Burt, whose department handles official and private entertaining across all royal residences, held a small electric fan close to the King as he chatted to some of the guests.

The historic building does not have air conditioning, and large fans were dotted around the rooms where guests could view stands showcasing green initiatives, and dozens of traditional hand-held fans were given to those attending.

It comes after a rare red extreme heat warning came into force for just the second time this morning, covering London, parts of the Midlands, and south-east Wales.

The Met Office has since extended it by three hours until 11.59pm on Thursday and to other southern areas across Dorset, Hampshire and Sussex.

An amber extreme heat warning has also been issued for Friday, which covers eastern and central England, and Saturday for parts of eastern England.

Alongside the warmth, there is also a chance of thunderstorms with a yellow warning in place for Thursday evening in south-west England.

The forecaster has predicted temperatures could reach 40C this week and said that the exceptional conditions pose a risk to life not just for vulnerable people, but across the wider population.

Britain’s highest temperature on record is 40.3C which was set in Coningsby in July 2022.

Some parts of Britain experienced overnight temperatures of above 20C, resulting in so-called tropical nights.

Older people have been urged not to leave their homes between 11am and 3pm during the heatwave.

Caroline Abrahams, Age UK charity director, said the red extreme heat warning needed to be taken seriously.

‘There are lots of simple precautions that older people can take to stay safe, such as keeping in the shade, drinking plenty of water and confining activities like walking or shopping to early or late in the day, certainly outside the hottest hours between 11am and 3pm,’ she said.

‘Keeping your home as cool as possible by closing curtains and windows during the day and opening them at night will make a difference too.’

As the country swelters under a ‘heat dome’, Sir Sadiq Khan has called for maximum and minimum temperature limits to be introduced for schools and workplaces.

The Mayor of London told LBC: ‘Sometimes in winter months schools and workplaces shouldn’t be too cold just as in summer they shouldn’t be too hot.

‘I think it’s really important for each individual employer and headteacher to make a common-sense decision based on what’s right for them.

‘For some children at school today, though, it’s probably cooler than their home and that’s why it’s really important to be pragmatic and dextrous when it comes to these sorts of decisions.’

Workers appear to have heeded the advice not to travel, with the number of people commuting into the City of London down by 12 per cent at 9am compared to this time last week.

According to O2 Motion’s anonymised data, the number of people travelling to King’s Cross was down 11 per cent, and it had fallen by 7 per cent in Westminster for the same period.

The looming heat emergency has already thrown parts of the country into chaos, with Great Northern passengers being forced to walk on the tracks yesterday afternoon when a train lost power ‘in the middle of nowhere’.

Commuters were left stuck for two hours without any air-conditioning in the blistering heat in what one person described as ‘a f***ing shambles’.

While Greggs has temporarily closed 11 stores today and tomorrow for the safety of staff and customers.

More than 1,000 schools are closing or reducing opening hours, rail operators have slashed timetables, Eurostar services have been cancelled and passengers are being urged to avoid travelling altogether as temperatures soar.

Katharine Birbalsingh, Britain’s ‘strictest’ head teacher, has kept her Michaela Community School in Wembley open.

But she said there was no point in schools staying open if pupils were asleep at their desks.

She told Times Radio: ‘When you’re very, very hot in a school, literally the children will be sleeping on the desks, the teachers can barely teach, you sort of think, what is the point?

‘Look, I am the strictest headmistress and all that, and the fact that even I am saying, look, I can understand why they’re doing it. I get it.’

Met Office chief forecaster Matthew Lehnert said: ‘This is exceptional heat for June with temperature records expected to be broken this week. Red warnings are reserved for the most severe events and we’re expecting significant impacts from this heatwave, with health issues likely, even beyond those who are more vulnerable to the heat.

‘High humidity is an additional factor for this heatwave which will mean the heat will feel much more potent for many.

‘When you couple all of this with the high overnight temperatures, with temperatures likely to stay above 20C for large parts of England and Wales, these combined impacts all increase the potential for significant impacts.’

The Cabinet Office held an official-level COBR meeting on Tuesday morning over the severe heatwave, with a Government spokesperson saying it will continue to closely monitor the situation.

Air conditioning units have also sold out at B&Q and Argos as Britons raced to buy the cooling equipment to help battle against the heatwave.

Motorists hoping to keep cool in their cars have been warned they could be hit with a fine under emission laws if they sit in stationary vehicles with the air-conditioning running.

The RAC said staying in a car with its engine idling causes air pollution, and the standard fine is £40 if caught by a police officer.

However, that doubles if you are caught by a civil enforcement officer.

Rod Dennis, a senior policy officer at RAC, said: ‘But while we’re all desperate to stay cool, just sitting in the car with the engine and air-conditioning running and going nowhere isn’t advisable.’

Dog owners have been told by the RSPCA not to take their pets out for a walk ‘at all because there isn’t a cooler time of day’.

Lauren Bennett, a registered veterinary nurse and dog welfare expert, said: ‘Just like people, it can be fatal, which is why we tell people to change their behaviour because our pets are completely under our control so the responsibility is on us.’

South East Water is asking customers to only use water ‘for hygiene, drinking and cooking’ and to pause ‘all hose use’ to ‘help keep taps flowing for everyone’.

And Wessex Water – which covers South West England, most of Wiltshire, and parts of  Gloucestershire and Hampshire – says people should take shorter showers, reuse paddling pool water, and use watering cans instead of hosepipes to help cope with the surge in demand for water.

Britain’s grid operator – the National Energy System Operator (NESO) – yesterday asked power suppliers to increase supply as demand soared.

A spokesman for the NESO said: ‘Our forecasts are showing tight margins on the electricity system for tomorrow evening. This is due to the impact of extremely high temperatures affecting Great Britain and the continent and low wind.’

The body, which is tasked with making sure the supply of electricity matches demand for it, said it had issued a so-called electricity margin notice.

This sends a message to the electricity market to ask for more capacity to be made available, allowing for production to increase if necessary.

The notices are more typically sent during winter when demand for heating is higher.

It comes as the high temperatures make Britain’s solar panels less efficient.  According to trade body Solar Energy UK, most panels are built to work from around -40C to 85C, but they generally perform best when the solar cells are closer to 25C or below.

Solar panels can lose between 0.34 and 0.5 percentage points of power output for every degree above 25C.

Meanwhile, construction workers in London today have said they may go home early because of the heat.

Johnny, who did not give his surname, told the BBC the conditions were ‘horrible’ but said ‘there’s work to be done’.

‘We’re all hot, and we’re all in the same boat. No one’s dropped down, touch wood,’ he said.

Yesterday afternoon, a Great Northern service from Moorgate to Stevenage lost power between Drayton Park and Finsbury Park.

It left passengers trapped in sweltering conditions for hours without any air-conditioning.

A Great Northern spokesperson said: ‘We are extremely sorry for the difficult and very uncomfortable conditions passengers faced when one of our services broke down yesterday.

‘This happened where power switches from the third rail of the Northern City Line to the overhead lines.

‘The safety of our passengers is our topmost priority which is why considerable efforts were made first to engage power and restart the train because the safest place for passengers is to remain on the train.

‘When this was not possible, railway staff evacuated people along the track to Drayton Park station.’

Parents are also facing major disruption after at least 578 schools in England and more than 500 in Wales announced full or partial closures amid concerns over dangerous classroom temperatures.

Almost 100 schools in Somerset are shut on Wednesday and Thursday, while around 100 schools in Buckinghamshire and dozens more across Gloucestershire have announced full or partial closures.

Other schools have relaxed uniform rules and allowed pupils to attend in PE kits rather than blazers and long trousers.

Transport officials have warned that rails, overhead power lines and signalling equipment could all be affected by the unprecedented temperatures, leading to delays and cancellations across the network.

National Rail warned of disruption across major routes until Friday, while Avanti West Coast said it would run fewer trains than usual and cautioned passengers that there remained ‘a risk of further disruption’.

London North Eastern Railway cut half of its services today and Great Western Railway has warned passengers to only travel if it is ‘essential’.

Chiltern Railways has also cancelled more than half of its services through the week, while Eurostar has axed several London-Paris trains because of the extreme weather.

The 1930s Pullman-style Northern Belle – one of the world’s poshest trains – has also postponed the £500-a-ticket sold-out trip to Chatsworth House in Derbyshire tomorrow.

The journey was meant to have taken 200 champagne-sipping passengers to the stately home, but organisers said ‘we do not believe we can give the comfort, or the care, that a day with the Northern Belle should carry’.

In Wales, a number of services have been cancelled by Transport for Wales.

The line between Llandudno and Blaenau Ffestiniog has been completely closed due to the ‘severe weather’.

Road replacement transport is running in place of the train services, with the closure expected to last all day.

Other routes affected are between Manchester and Cardiff, Coryton and Penarth, Ebbw Vale and Cardiff, Bridgend and Maesteg, Chester and Wrexham, and Pontypridd and Cardiff Bay.

On top of this, the Army has cancelled ceremonial operations – including the Changing of the Guard at Buckingham Palace – in London and Windsor to protect its soldiers’ ‘wellbeing’ while lidos are fully booked days in advance.

Forecasters say temperatures could climb to 39C in London and the South East on Thursday.

Some computer models have suggested the mercury could edge even higher and challenge Britain’s record of 40.3C, set in Lincolnshire during the historic July 2022 heatwave.

The Met Office warned that maximum temperatures could exceed 37C for two to three consecutive days across parts of southern England and Wales, with some locations potentially reaching between 38C and 40C.

High humidity is expected to make conditions feel even more oppressive, while tropical nights with temperatures remaining above 20C will offer little respite after dark.

Grahame Madge, a Met Office spokesman, said: ‘The Met Office is flagging 39C as a headline maximum temperature on Thursday, most likely for somewhere in London or the South East.

‘It is possible we could see temperatures higher than the 39C if the final values are at the upper end of our narrow range.

‘It is important to remember that the temperature value is only one element of this extreme heatwave story.

‘The other major factor is the high humidity, which for many will make the intense heat even harder to endure.’

The warning area stretches from London to Swansea and from Somerset to Birmingham, with officials describing the weather event as a potential national emergency.

The Met Office said: ‘An exceptional spell of hot and humid weather is expected across this region, with impacts to the general population highly likely.’

In an unusually stark assessment, forecasters warned of ‘population-wide adverse health effects’, serious illness and danger to life, major changes to daily routines, disruption to workplaces and transport networks, and even the possibility of failures affecting power, water, gas and mobile phone services.

The agency also warned of an increased risk of water-related fatalities as millions seek relief at beaches, rivers and lakes.

The heatwave is being driven by a powerful area of high pressure parked across western Europe – known as a heat dome – which has trapped superheated air across the continent and sent temperatures soaring above 40C in parts of France, Spain and Italy.

The UK Health Security Agency has issued red heat health alerts across much of England, warning that extreme temperatures are likely to affect the health and wellbeing of the wider population and place additional pressure on health and social care services.

Hospitals have begun implementing emergency plans, while NHS trusts have advised patients attending appointments to carry water and check travel arrangements before setting out.

The London Fire Brigade has issued warnings over an elevated wildfire risk, urging people not to use disposable barbecues in parks or open countryside.

Emergency planners are also monitoring air quality after London Mayor Sir Sadiq Khan activated a high pollution alert for the capital amid concerns the stagnant weather pattern could trap harmful pollutants over the city.

Even the Army has been forced to scale back ceremonial duties in London and Windsor.

In a statement posted on X, the Army in London said: ‘Due to extreme heat this week, Ceremonial Operations in London & Windsor will be changed or cancelled. The wellbeing of our soldiers, horses and the public will always come first.’

Meteorologists say one of the biggest concerns is the lack of overnight cooling.

Met Office deputy chief forecaster Tom Crabtree warned: ‘The forecast heatwave is developing into an impactful severe weather event, with record-breaking June temperatures and very high humidity.

‘The combination of heat and humidity will be oppressive and bring impacts across society from public health and infrastructure, to power and water supplies.

‘As well as very high daytime temperatures, there will be consecutive nights where temperatures do not drop below 20C, which is called a Tropical Night.

‘This will make it very hard for people to recover from the daytime heat, exacerbating the heat stress impacts.’

Tuesday already saw temperatures reach 34.6C in Wisley, Surrey, making it one of the hottest June days on record.

The Met Office has urged people to stay hydrated, avoid strenuous activity during the hottest part of the day, keep homes shaded and check regularly on elderly relatives, neighbours and vulnerable people.