Hottest June day on record
Britain has recorded its highest temperature for June.
Temperatures soared to 36.1C in Gosport, Hampshire, surpassing the previous record of 35.6C which was set in Southampton in 1976, a summer renowned for its high temperatures. It marks the highest reading since records began in 1884.
Passengers have been told not to travel by rail unless "absolutely necessary", as speed restrictions imposed during the heat have caused widespread cancellations and delays. Advertisement
Advertisement
Extreme heat can cause tracks to expand or overhead wires to sag, sparking safety concerns.
Motorists on the M25 have also been caught in six miles of congestion after a section was closed following a serious crash.
The heatwave has hit Wimbledon qualifying, which was suspended after the automated line-calling system suffered a meltdown, with the All England Club unable to call on line judges.
The Met Office has issued a red extreme heat warning for much of southern and central England and Wales, with amber warnings also extending into Friday and Saturday.
The forecaster has issued a yellow thunder warning for the south-west of England from 6pm to 11.59pm on Thursday. Advertisement Advertisement
09:04pm
That's all for today
Thank you for following our live coverage of the heatwave.
Here is a summary of the day's biggest developments:
Passengers were told not to travel by rail unless "absolutely necessary", as speed restrictions imposed during the heat have caused widespread cancellations and delays.
Motorists on the M25 were caught in 10 miles of standstill traffic after a section was closed following a serious crash, with paramedics treating those who were stranded for heat-related illnesses.
Sir Sadiq Khan called for the introduction of minimum and maximum working temperatures.
The heatwave was estimated to have cost the UK's nine largest cities GBP280m in lost productivity as thousands of commuters chose to stay at home.
In Totton, a suburb of Southampton, police divers were searching for a missing 15-year-old boy who was last seen swimming in a lake at 1.35pm.
Wimbledon qualifying was suspended as the automated line-calling system suffered a meltdown.
Solar panels struggled in the heat, forcing gas power stations to fire up production.
09:01pm
MP calls for M25 evacuations
The Labour MP for Folkestone and Hythe has called for the evacuation of drivers stuck on the M25.
Advertisement Advertisement
In a post, Tony Vaughan addressed police and highways teams as he said: "Please sort this out urgently. People need water and some may need evacuation.
You have protocols for this situation - please implement them - this is an emergency!"
He said one constituent had been stuck on the M25 near Oxted for eight hours, adding: "It is 40 degrees in her car. She has kids with her. She is running out of water.
"The person from the car in front has been airlifted to hospital with dehydration.
Police seem to be saying it's not their job to give out water."
Kerry Matthews told the BBC she was stuck for five hours and had to turn her air-conditioning off to save petrol. She said she was left feeling "very wobbly" by the time she made it to the petrol station. Advertisement
Advertisement
In a social media post, a woman said there were "elderly people, babies, animals, [and] people with health conditions" who had been stuck on the tarmac for hours.
08:37pm
Hospital declared critical incident as cooling system fails
Queen Alexandra Hospital in Portsmouth declared a critical incident after a cooling system failed during the heatwave.
Mark Orchard, deputy chief executive and chief financial officer of Portsmouth Hospitals University NHS Trust, said: "The unprecedented pressures created by the current heatwave, combined with the failure of a number of our chiller units, have led to significant disruption across several of our services."
He said services impacted include "digital systems and critical clinical services, including theatres, cardiac catheter laboratories, and diagnostic scanning facilities". Advertisement Advertisement
Some planned procedures and appointments have been "stood down", a statement from the hospital added.
Patients have been warned the hospital is "very hot" so to limit the number of people accompanying them to appointments.
08:32pm
Only travel if 'absolutely necessary', says Network Rail
Rail passengers have been advised to only travel if "absolutely necessary" on Thursday and Friday.
Network Rail has advised passengers in areas where weather warnings are in place to avoid any non-essential travel as it warned of "high risk of disruption" to services.
It said that trains would operate at reduced speeds and on amended timetables meaning journeys were likely to take longer and there was a higher risk of disruption.
Advertisement Advertisement
Jake Kelly, deputy chief executive of Network Rail, said: "Very high temperatures - like we are seeing in Great Britain and across parts of Europe - put significant strain on the railway, so our priority is to keep passengers safe while keeping services running.
"We're asking passengers to think carefully about their plans and only travel if it's absolutely necessary in the areas most affected by the extremely high temperatures that are being recorded.
"If you do need to travel, please take extra care by planning ahead, allowing more time for your journey and bringing water to stay cool and comfortable."
Passengers have been advised to wear cool clothing and consider taking handheld fans for any journeys - TOBY SHEPHEARD/AFP
08:16pm
'Hot, humid and sunny end to the day'
The Met Office has forecast another "hot, humid and sunny" end to the day for many this evening. Advertisement
Advertisement
Temperatures are expected to remain as high as 29C in London and Cardiff at 10pm.
High pressure is expected to move away to the east of the country later this week, bringing cooler conditions from the west but also increasing the chance of showers and thunderstorms
08:08pm
The reason your train is slower in heatwaves
If your rail journey was disrupted during this week's heatwave, you may have been the victim of "sun kink".
The dangerous phenomenon occurs when steel rail tracks expand and buckle in extreme heat, sometimes warping violently into S-shaped curves in a matter of seconds.
Sun kinks typically become a severe risk when air temperatures reach 30C (85F to 90F) and above, with the steel getting significantly hotter as it bakes in the sun. Advertisement Advertisement
Thermal expansion forces the steel to lengthen, but because the tracks are fixed, there is nowhere for it to go, so it must bend sideways or upwards.
Ripples in the line can cause trains to derail, which is why so many services have been cancelled or run with speed restrictions this week, bringing travel chaos to commuters already dealing with sweltering temperatures.
These tracks in Adelaide, Australia, have buckled due to extreme heat - something UK tracks are now experiencing - Calum Robertson/Adelaide Advertiser
08:03pm
Shakespeare's Globe cancels performances
Shakespeare's Globe theatre in London has cancelled performances citing the health and safety of its artists and staff.
The matinee performance of Mother Courage and Her Children and the 7.30pm production of A Midsummer Night's Dream were cancelled on Wednesday.
Advertisement Advertisement
A 2pm performance of A Midsummer Night's Dream on Thursday has also been cancelled.
"The health and safety of our audiences, volunteers, artists and staff are always paramount," a spokesman said, adding: "Taking into account the current weather warning, we have been assessing all activity on site, with welfare, health and safety at the centre."
Guided Tours and on-site education activity is continuing daily as scheduled.
The theatre said measures are put in place for all adverse weather conditions at the open-air stage - Oli Scarff/Getty
07:31pm
Motorists stuck on M25 treated for heat-related illnesses
Several people stranded in traffic on the M25 after a crash are being treated for heat-related illnesses, South East Coast Ambulance Service has said.
The M25 clockwise remains closed within junction six in Surrey, with drivers stuck on the road for "several hours" as temperatures soared.
The ambulance service says coach passengers are among those being treated, without specifying how many people are unwell.
National Highways said there was 10 miles of congestion in the area, with traffic being released in one lane and via a slip road.
Heavy traffic means ambulances are still trying to reach people on the road near Godstone.
One social media user wrote: "Many of us stuck on the road and can't get off. Some people have no water, temps 35 degrees."
A section of the M25 has been closed after a van and a lorry were involved in a serious crash
07:12pm
Climate change making extreme temperatures the norm, says scientist
Climate change is making temperatures previously considered extreme the norm, a Met Office scientist has warned.
Amy Doherty, a science manager at the Met Office, said: "If confirmed, a new June daily temperature record would be significant, especially following on the heels of the recent records set in May.
"The new record provides further evidence that temperatures previously considered extreme are becoming increasingly common as a result of human-induced climate change."
Temperatures could rise even higher on Thursday, the Met Office said.
06:53pm
France records hottest day since records began
France has recorded its hottest day since measurements began in 1947, the national weather agency said.
The national temperature indicator - an average of daytime and nighttime temperatures across 30 stations - reached 30C, Meteo-France said, citing provisional data, a day after a record 29.8C was measured on Tuesday.
A group of teenagers throw water at a cyclists next to the Canal Saint-Martin in Paris - SIMON WOHLFAHRT/AFP
06:27pm
Heatwaves risk interest rate hikes, says rate-setter
More frequent heatwaves risk forcing the Bank of England to put up interest rates to prevent surging prices, a rate-setter has warned.
Swati Dhingra said that climate change is already pushing up food prices, as extreme weather causes heatwaves, droughts and floods, which destroy crops around the world.
Britons risk seeing higher prices in shops and interest rates rise more often, as climate change makes such weather more common, Ms Dhingra suggested in a speech.
The economist, who is an external member of the Bank's panel of rate-setters, warned that climate change meant "increasingly frequent and severe extreme weather events disrupt supply, particularly in the agricultural sector."
The rate-setter said the impact of extreme weather like heatwaves and droughts on prices in shops is "likely to intensify".
Policymakers will find it increasingly difficult to avoid raising interest rates in response to climate change, she added.
Ms Dhingra said: "Two features make [climate-related shocks] particularly challenging: their salience for households, especially through food and energy prices, and their increasing frequency and severity, which make their first-round effects progressively harder to look through."
06:15pm
Temperature record edges higher
The June heat record has edged higher.
The highest temperature recorded today is now 36.1C at Gosport, Hampshire.
06:06pm
The King keeps cool at St James's Palace reception
The King had to be fanned by one of his top aides as he attended a reception at St James's Palace.
Retired Vice Admiral Sir Tony Johnstone-Burt, the Master of the Household, held a small electric fan close to the King as he spoke with guests at the environmental reception.
The gathering was aimed at accelerating momentum on super-pollutant action and was hosted by the Department for Energy Security and Net Zero, with speakers including Mia Mottley, the prime minister of Barbados, and UN Secretary-General Antonio Guterres.
Vice Admiral Sir Tony Johnstone-Burt holds a small battery powered fan for the King - Yui Mok/PA
Ed Miliband began by delivering "safety announcements", telling guests there was a nurse on site.
He added: "Here we are in London on a 35C day.
This didn't used to be normal, but unfortunately it is now the new normal, and we know that reducing methane emissions and other super-pollutants is one of the best things we can do to act on the climate crisis."
The King dabs his forehead with a handkerchief - Yui Mok/PA
Ed Miliband speaks at the London Climate Week reception - Yui Mok/PA
05:44pm
Almost 1 in 10 trains cancelled amid heatwave
Nearly one in ten rail services across the country has been cancelled or severely delayed amid the ongoing heatwave.
Data shows that nine per cent of scheduled train services for Wednesday were either cancelled or delayed by more than 30 minutes, according to the trains.im website.
Worst-affected was Avanti West Coast (AWC), which at 5pm had had nearly half (46pc) of its 183 services at that point in the day cancelled or severely delayed.
An AWC spokesman said services had been intentionally cut back from Liverpool and Manchester to London, adding that signalling problems at Liverpool South Parkway station combined with a track defect at Brinklow Junction, near Coventry and Rugby, had worsened the situation.
London North Eastern Railway (LNER) chief executive David Horne said this morning that half of all trains between Leeds and London would not run. He added, in a post to X: "Tickets dated today or tomorrow will be accepted on alternative dates up until 30 June."
Southeastern, in contrast, has so far only cancelled 5pc of planned trains on Wednesday. The train company previously said it is focusing on getting as many of its air-conditioned trains as possible out on the tracks.
Water bottles are laid out for people to take at Kings Cross station in London - TOBY SHEPHEARD/AFP
05:28pm
MRI scanners at hospital fail in extreme heat
MRI scanners have reportedly stopped working at a hospital after their cooling systems failed in the extreme heat.
Hundreds of patients have had their appointments cancelled and a critical incident has been declared at Norfolk and Norwich University Hospitals, according to the Eastern Daily Press.
At least 254 outpatient appointments are said to have been cancelled.
Chris Cobb, chief operating officer at the hospital, said: "Due to the hot and humid weather, the cooling systems in our MRI scanners are failing and we currently have no working MRI scanners at the Norfolk and Norwich University Hospitals NHS Foundation Trust, this includes the onsite inpatient MRI scanners and the Community Diagnostic Centre outpatient MRI scanners.
"We have therefore declared a critical incident."
05:20pm
Teenager missing after swimming in lakes
Police marine units have joined the search for a missing 15-year-old boy last seen swimming in Hampshire.
The teenager was reported missing at 1.35pm on Wednesday after entering the water at Testwood Lakes, near Totton, Southampton.
A Hampshire Constabulary spokesman said: "A multi-agency operation is under way following a report that a 15-year-old boy is missing after he was last seen swimming at Testwood Lakes near Totton.
"This was reported to police at 1.35pm on Wednesday 24 June and the area is currently off limits while our search operation is ongoing.
Please avoid the area at this time."
05:16pm
Supermarket fridges break down
Supermarket fridges are breaking down across the UK amid the soaring temperatures.
Stores including Sainsbury's and M&S have reportedly been hit by outages.
Rupert Ashby, CEO of the British Frozen Food Federation, said the issue appeared to arise from out dated refrigeration systems which struggle to cope with "regular periods of severe heat that are becoming more common."
He also told The Grocer that "retail freezers are under a lot of pressure when it is hot because we tend to buy more frozen. Therefore, the system will be working overtime to keep it cool. The older the system, the more likely it could break down."
05:05pm
Heatwave to cost cities GBP280m in lost productivity
This week's heatwave will cost the UK's nine largest cities GBP280m in lost productivity, according to estimates by the Centre for Economics and Business Research (CEBR), as companies grapple with the effects of extreme heat.
The City of London will face a near GBP180m blow from lost labour productivity, making it the worst affected city.
The hit to the nation's financial capital comes despite the widespread introduction of air conditioning in offices.
Dan Smith, an economist at CEBR, said: "This week's heatwave is expected to incur significant costs to the UK economy.
"However, the cities we consider still only account for around 11pc of the UK workforce, suggesting that the true UK-wide costs are larger."
Mr Smith explained that the estimates only show the impact of lost labour productivity because of the extreme heat.
He added that the indirect economic hit from reduced footfall in stores, falling crop yields and damage to infrastructure is likely to be even higher.
Swimmers at Tooting Bec Lido in south London - Ben Whitley/PA
04:53pm
Polanski: It's time to heat-proof Britain
Zack Polanski has said it is time to heat-proof Britain because "kids are fainting in classrooms and workers are sweltering".
The Green Party leader has called for every home to receive "heatproofing" and for "cooling measures" to be installed in schools, hospitals and care homes.
Mr Polanski also echoed Sir Sadiq Khan's calls for the introduction of a maximum workplace temperature limit.
04:30pm
Transport for Wales slashes services
Transport for Wales has cancelled services across Wales because of the extreme heat and a shortage of trains.
Routes affected are between Manchester and Cardiff, Coryton and Penarth, Ebbw Vale and Cardiff, Bridgend and Maesteg, Chester and Wrexham, Llandudno Junction and Blaenau Ffestiniog, and Pontypridd and Cardiff Bay.
Most routes will remain cancelled until the end of the day, the operator said.
04:30pm
Temperatures continue rising to 36C
A new record for June has been set as temperatures continue to rise.
The provisional June record now stands at 36C, which was recorded in Wisley in Surrey and Gosport in Hampshire.
04:25pm
Record temperatures are 'sobering', says Met Office scientist
The temperatures recorded in June this year are a "sobering" reminder of the implications of climate change, the Met Office's chief scientist has said.
Prof Stephen Belcher said: "Human induced climate change has made events like this more likely and more intense.
"To see temperatures like this in the UK in June is sobering.
Events like this bring home the implications of climate change, with very high temperatures and humidity bringing significant health implications from heat stress, as well as impacts to a range of sectors such as transport, energy and water supply."
Players cool down during a Barbarians training session at Wasps RFC in London - Steve Bardens/Getty
04:01pm
Temperature breaks record for June
Britain has recorded its highest temperature for June since records began.
Temperatures have soared to 35.7C in Charlwood, Surrey, surpassing the UK's previous June temperature record of 35.6C in 1976.
The location of Charlwood weather station is around half a mile from Gatwick Airport.
The heatwave, which has led to health warnings, school closures and transport disruption, is driven by a "heat-dome" settling over western Europe that has brought extreme conditions across the continent.
Friends fish in the river Cray after their nearby school closed due to the hot weather - Dan Kitwood/Getty
03:53pm
Motorists stuck in hot cars on the M25
Motorists have told of being stuck in hot cars on the M25 after a section was closed following a serious crash.
Traffic could be seen backing up while emergency services dealt with an incident on the clockwise carriageway between junctions six and seven, near Godstone.
Surrey Police has warned motorists to expect lengthy delays and urged drivers not to leave their vehicles if they are between junctions five and six.
National Highways said there was six miles of congestion in the area and no estimated time for the carriageway reopening as it requires resurfacing.
Traffic is being released via the junction six exit slip road.
"I feel so sorry for everyone involved, including people stuck in ridiculously hot vehicles," one social media user wrote.
Another said: "Still sat on M25, four hours now in the boiling heat."
03:45pm
Extreme heat conference cancelled over extreme heat
A conference in central London on the topic of how the world can adapt to extreme heat has been cancelled over soaring temperatures.
The event, titled Extreme Heat: Improving governance and strengthening action around the world, will no longer go ahead at the London School of Economics' Shaw Library on Wednesday evening.
Part of London Climate Action Week, the event had hoped to share new analysis of extreme heat governance progress and challenges across countries where the Zurich Climate Resilience Alliance operates.
Organisers said the university's building did not have any cooling mechanisms in place "like most buildings in London".
A teacher sprays water on pupils at L'Ecole des Petits in Fulham, London - Kevin Coombs/Reuters
03:30pm
Scotland records hottest day of the year
Scotland has recorded its hottest day of the year and there were warnings of potential travel disruption as the hot weather is expected to continue in the coming days. Temperatures reached a high of 29.4C at Dyce in Aberdeen on Tuesday, according to Met Office data.
Meanwhile, the BBC has reported that temperatures have so far reached 35.3C in Gosport, Hampshire, and Wisley, Surrey, just shy of the June record of 35.6C.
People sunbathing in Battersea Park, London - Jordan Pettitt/PA
03:21pm
Britain not prepared for climate change, says Sadiq Khan
Sir Sadiq Khan said Britain has not adapted to deal with climate change as he conceded the capital's transport infrastructure was buckling in the heat.
Speaking as he visited The Aldgate School, the Mayor of London urged the public to "bear with us" as they face public transport delays during the heatwave.
He said: "What used to be a once in a generation occurrence, events of biblical proportions, now takes place every year, whether it's heatwaves, whether it's flash flooding, whether it's lightning, whether it's thunder - we as a city, we as a country, haven't adapted to be resilient to the consequences of man-made climate change."
Sir Sadiq Khan during a visit to Aldgate School in west London - Macie Lewis/PA
Sir Sadiq added: "People across the country can expect to see delays in public transport today, tomorrow and the rest of this week that's a consequence of the extreme heat.
"People across the country I am afraid will have to bear with us - our public transport system is not made for temperatures approaching 40C.
"Forty per cent of Tubes are now air conditioned with more going forward. I will be publishing very soon a plan of what more we need to do to deal with heat."
A person uses a portable fan on an underground train in central London - TOBY SHEPHEARD/AFP
03:15pm
Thunderstorm warning issued
The Met Office has issued a yellow thunder warning for the south west of England.
The yellow warning, which could see storms brining winds of up to 60mph, lightning, hail and heavy rain, will last from 6pm to 11.59pm on Thursday.
Those in an area at risk to flash flooding are encouraged to prepare an emergency flood kit and the public has been advised to protect their property by ensuring moveable objects are secured, such as bins, garden furniture and trampolines.
The warning covers Cornwall, Devon, Somerset and Dorset.
03:08pm
Older people advised to stay at home between 11am and 3pm
Older people have been encouraged to avoid leaving their home between 11am and 3pm during the heatwave.
Caroline Abrahams, charity director at Age UK, stressed that the red extreme heat weather warnings needed to be taken "seriously" and acted upon.
She said: "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.
"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."
She added: "We hope anyone in this position, and older people more generally, will take extra care over the next few days and follow the excellent advice the Met Office and ourselves at Age UK have published on how to stay well when the temperatures soar.
We also call on the public at large to look out for older people around them, to help them safely navigate the next few days."
People shelter from the sun on a punt along the River Cam - CHRIS RADBURN/AFP
03:04pm
Horse racing meets to finish early
Horse racing meets in Yarmouth and Doncaster will finish early owing to the soaring temperatures.
The British Horseracing Authority (BHA) said the fixtures on Friday will be staged earlier in the day to avoid racing when temperatures are at their highest.
Doncaster's first race is scheduled for 10:15, with the final race at 13:15.
Yarmouth's fixture will now begin at 10:30 and the last race will be at 13:30.
02:23pm
Katharine Birbalsingh: No point schools staying open if pupils asleep at their desks
Britain's so-called strictest headteacher said there was no point in schools staying open if pupils were "just asleep on their desks".
Katharine Birbalsingh, head of Michaela Community School in Wembley, said her school had remained open during the heatwave but conceded it "becomes very difficult" for schools without air conditioning.
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."
Pupils eat ice lollies during class at the Harris Academy Primary Mayflower school, in Grays - Jack Taylor/Reuters
02:14pm
London Ambulance Service dispatches hundreds more crews during extreme heat
The London Ambulance Service (LAS) has put more than 400 extra ambulance crews on the roads across the capital during the heatwave.
It said that emergency calls linked to the hot weather are increasing, with crews responding to more people who are fainting, struggling to breathe and becoming unwell in the heat.
Chief Executive Jason Killens KAM said: "This is an exceptional heatwave and the red alert means there is a risk to life, even for people who are normally fit and well.
"We are already very busy and we're expecting significant pressure over the coming days, with more patients becoming seriously unwell."
During May's heatwave, the LAS handled more than 8,000 calls to 999 in a single day, making it the highest level of demand since the height of Covid.
Hundreds more ambulance crews have been made available to those struggling in the heat - London Ambulance Service
01:50pm
Solar panels overheat as temperatures soar
Gas power stations across the UK have been ordered to fire up production as soaring temperatures trigger a slump in solar energy.
The National Energy System Operator (Neso) issued a power supply warning overnight as the country braces for temperatures near 40C on Wednesday and Thursday.
It is the first time the grid operator has been forced to issue such an alert during the summer months.
Gas plants have been urged to ramp up output to deal with high levels of demand expected on Wednesday night as homes and offices turn up the air conditioning to endure the heatwave.
The notice comes as soaring temperatures make Britain's solar farms less efficient, putting further strain on the power grid. Solar panel efficiency typically drops by 0.3pc to 0.5pc for every degree that a panel's temperature rises above 25C.
01:37pm
Wimbledon qualifying suspended as automated line-calling falters in heat
Wimbledon qualifying was suspended after the automated line-calling system suffered a heat-related meltdown, with the All England Club unable to call on line judges.
Players left the courts at the Roehampton event this afternoon after officials made the decision that chair umpires could not be entrusted with line-calls.
There are no reserve line crews available for qualifying, in case of malfunctions, unlike at next week's main-draw Championships at the All England Club proper.
At the time of the interruption, 16 second-round singles matches were in progress in Roehampton - the second-string venue, a couple of miles from Centre Court, where Wimbledon is forced to host its qualifying event.
Wimbledon brought in Hawk-Eye Live to replace human line judges last summer, but there were teething problems from the start.
An operator accidentally turned Centre Court's line-calling off for more than six minutes during a fourth-round match, while British players Jack Draper and Emma Raducanu were among those who publicly questioned the accuracy of decision-making.
01:23pm
Pictured: Chicken keeps cool
Farmers and livestock owners have been instructed that livestock shouldn't be moved between 8am and 8pm to keep animals safe - Joann Randles
12:58pm
Water park closes... because it's too hot
A water park in Hertfordshire has closed because it is too hot.
London Colney Parish Council, which owns and operates the Watersplash Splash Park, also advised people "do not leave their homes".
It announced that the venue would be closed on Wednesday and Thursday as a result of the Met Office's extreme red weather warning of heat.
A sign stuck on the entrance board of the site, said: "It is advised that people DO NOT leave their homes.
"Due to the synthetic surface in the splash park, the ground may become extremely hot during periods of high temperatures and could cause burns to skin."
Families hoping to cool off with a dip were left disappointed and instead advised to stay at home - Jacqueline Lawrie/LNP
12:27pm
Drivers warned against idling with air conditioning on
Motorists seeking to cool down by sitting in stationary cars with the air conditioning on are being warned they could be fined under emissions laws.
The RAC said remaining in a vehicle with its engine idling causes air pollution.
The standard fine is GBP40 if caught by a police officer or GBP80 from a civil enforcement officer.
Both are halved if paid within a specific time.
But some local authorities use their powers to impose larger fines.
In London, Islington Council said its enforcement officers issue GBP110 fines to people who refuse to switch off an idling engine after being asked.
RAC senior policy officer Rod Dennis said: "Air conditioning is a game-changer in modern vehicles, making otherwise uncomfortable journeys by road a genuinely pleasant experience.
"We even advise those driving vehicles without air-con to consider delaying any non-essential trips this week until the heatwave passes.
"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.
"Due to the air pollution this causes, you risk a fine from a police or civil enforcement officer."
In 2019, the Conservative government announced plans to introduce higher fines for drivers who idle, but this never took place.
Lord Chris Grayling, then-transport secretary, said at the time that combating idling would be "an easy way to drive down dangerously high levels of pollution".
12:00pm
Amber heat warning issued for Saturday
The Met Office has issued an amber warning for extreme heat covering parts of east and south-east England on Saturday.
Temperatures will be a few degrees cooler than the previous days, but are still expected to exceed 30C widely in the area, which stretches from the Sussex coast to Lincolnshire, peaking around 32C to 34C in London or East Anglia, the weather service said.
Night temperatures are unlikely to fall below the high teens Celsius for most, with some places probably still in the low 20C, while high humidity will continue.
11:45am
Workers opt to stay at home during heatwave
Thousands of workers who normally commute to central London decided against travelling to the capital on Wednesday.
The number of people who made the trip during today's heatwave dropped sharply following advice to avoid travel unless "absolutely necessary".
Figures show travel into the City of London was down 12pc at 9am this morning compared to this time last week.
Anonymised data from O2 Motion also showed the number of people commuting into King's Cross fell 11pc, while travel into the West End fell 13pc during the same period.
Hundreds of schools have closed across the country, meaning parents have been forced to stay at home and look after children.
Travel into Bristol, where dozens of schools have shut, dropped by 21pc on Wednesday.
11:33am
Do you have photographs from summer of 1976?
11:27am
Pictured: Commuters endure heat during London rush hour
Fan sales have rocketed across Europe as the latest heatwave takes hold - TOLGA AKMEN/EPA/Shutterstock
Passengers arrive at Waterloo as rail networks across the country were subject to numerous cancellations and delays because of the heat - Toby Melville
Passengers have been told to 'only travel if absolutely necessary' on Wednesday and Thursday - Toby Melville
11:09am
Rome among 16 Italian cities on red alert for extreme heat
Italy has been in the grip of an intense heatwave for days, with temperatures in the mid-30s centigrade across the country.
The government has today declared a red alert for 16 of the country's cities, including Rome, Venice, Turin, Verona, Milan, Florence and Bologna.
The list will increase to 17 cities on Thursday, when the coastal city of Bari in the southern region of Puglia is added.
The red alert means that the extreme heat poses a danger to the health of the general population, not just vulnerable groups such as young children and the elderly.
The heatwave is expected to last all this week and into next week.
11:06am
Amber heat warning issued for Friday by Met Office
The Met Office has issued a further amber warning for heat on Friday.
It will come into effect at midnight on Thursday night and last until 11.59pm on Friday, covering eastern and central England.
Temperatures in these areas are widely expected to exceed 30C, with the hottest of these set to potentially peak at 38C.
Met Office spokesman Grahame Madge said: "As the forecast continues to evolve, we may need to issue further updates once more detail becomes clear."
The amber warning will come into effect straight after the current red and amber extreme heat warnings covering nearly all of England and Wales end.
10:52am
Watch: Passengers forced to walk along track after train breaks down
Passengers of a Great Northern train were forced to walk along railway tracks after it broke down during Tuesday afternoon's heat.
Customers were not allowed to leave the carriage for nearly two hours as engineers tried to fix the problem.
Having broken down at 3pm, those onboard the Moorgate to Stevenage service were finally allowed to disembark at 4.45pm.
They then had to walk to Drayton Park station to continue their journeys.
Great Northern said it was "extremely sorry for the difficult and very uncomfortable conditions passengers faced".
A spokesman said: "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."
10:34am
RSPCA: Don't take your dog out for walks
Dog owners have been told not to take their pets out for a walk because there "isn't a cooler time of day".
The RSPCA advised that if dogs are taken out, they are kept to shaded areas with minimal physical exercise.
Lauren Bennett, a registered veterinary nurse and dog welfare expert with the charity, said: "With this red weather warning, actually we would advise probably not to walk your dogs at all because there isn't actually a cooler time of day."
"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."
10:22am
Readers have their say
10:15am
'Tropical night' for areas all over the country
The Met Office has confirmed overnight temperatures stayed above 20C in "numerous areas".
The "highest overnight lows" were recorded at:
Brize Norton: 22.3C
Heathrow: 22.1C
Wittering: 21.4C
Swanage: 21.4C
Cranwell: 21.4C
Nottingham: 21.3C
10:01am
France set for yet another heatwave in early July
France faces a likely third heatwave within weeks, the ecology minister warned on Wednesday, after the country recorded its hottest day since records began.
Monique Barbut said Meteo France expected a "relative pause" next week, but warned there was a "strong probability" of a return to "extreme heat" from the week of July 6 until Bastille Day.
Asked whether that meant a third heatwave, she replied: "Exactly."
Meanwhile, Eurostar has reduced services between Paris and London as Europe's heatwave disrupts rail networks on both sides of the Channel.
The operator said two trains a day between the French and British capitals would be cancelled until midnight on Thursday because of "adverse weather conditions".
The decision came after France recorded its hottest day since records began in 1947, with temperatures locally topping 40C, while southern England was also under extreme heat warnings.
Passengers have been offered free exchanges or refunds.
09:52am
Very high risk of wildfire on 'tinder dry' Dartmoor
The risk of wildfires on Dartmoor is "very high" as temperatures continue to climb throughout this week.
Simon Lee, who is head ranger at the Devon National Park, said conditions on the moor were "tinder dry".
"It's incredibly hot and it's incredibly dry," he told the BBC.
"Fires can start and spread very quickly and can be absolutely devastating for communities, livestock, wildlife.
"We're asking people to leave their BBQ at home and bring a picnic instead, and reminding people that open fires are not permitted on Dartmoor".
In May 2025, a large wildfire destroyed more than 1,200 acres of moorland in a blaze that lased almost 24 hours.
Since then, steps have been taken to improve wildfire preparedness, including cutting an additional 25 miles of firebreaks and creating better access for emergency vehicles.
09:28am
Pictured: Emus cool off at Hertfordshire Zoo
Emus and other animals at the zoo may have to deal with temperatures of 40C on Wednesday and Thursday - Hertfordshire Zoo / SWNS
09:17am
Grid operator demands more power as heatwave strains network
Britain's grid operator has asked power suppliers to ramp up production as soaring temperatures pile pressure on the energy system.
The National Energy System Operator (Neso) issued a rare summer power supply warning overnight as the country braces for temperatures near 40C on Wednesday and Thursday.
While sunny weather has boosted renewable generation, extremely high temperatures are simultaneously reducing the efficiency of solar panels and gas-fired power stations.
Demand for electricity has surged as homes and offices turn up the air conditioning to endure the heat wave.
Britain was facing a 1.9 gigawatt shortfall in its "margin" for Wednesday night - the buffer between available power generation and total consumer demand - according to an alert at 9pm on Tuesday from Elexon, the company that manages the electricity trades that keep Britain's lights on.
09:06am
More than one in 10 trains cancelled or delayed by more than half an hour
More than one in 10 (11 per cent) of services across Britain were either delayed by more than half an hour or cancelled entirely on Wednesday morning, according to figures.
London North Eastern Railway (LNER) said it had cut half of its services.
David Horne, the managing director of the train operator, said all Lincoln to London services and half of its Leeds to London journeys will not run.
He announced there are also going to be amendments to the Hull and Middlesbrough services.
08:39am
Call-outs higher because of heat, says AA, as drivers warned to check vehicles
The Automobile Association (AA) has said call-outs were six per cent higher than normal because of the extreme heat on Tuesday.
Motorists were warned not to "underestimate the strain" hot weather can have on their vehicles, particularly older cars that have not been serviced recently.
Drivers were encouraged to check tyre pressures, coolant and oil levels before setting off and to watch for signs of overheating to prevent breakdowns.
An AA spokesman said: "Yesterday, overall workload was around 6pc above planned levels, reflecting increased demand for our services across the UK.
"While the number of tasks our patrols attended remained in line with expectations, the nature of incidents they attended were considerably more challenging than usual.
"As temperatures remain high, drivers should not underestimate the strain that hot weather can place on vehicles. We also advise occupants to use caution when entering a vehicle in hot weather, as seats, trim and other interior surfaces can quickly reach temperatures that may cause discomfort or minor burns."
08:26am
Electrical fault means free travel from Brixton
Commuters from Brixton were granted a free journey on Wednesday morning as a result of an electrical fault.
Londoners travelling from the south London tube station were met with a sign telling them not to tap out at their destination, to avoid being charged.
The electrical fault comes as Britain's electricity grid operator issued an industry warning that the power supply could be squeezed on Wednesday evening as extreme heat puts pressure on the system.
Neso, 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.
However, he extreme heat can put pressure on the electricity system by making processes less efficient, including nuclear power plants, gas stations and water cooling systems.
It also means people are using more electricity for fans and air conditioning to keep cool.
The sweltering heat was made slightly more bearable on Wednesday as commuters were granted a free journey from Brixton
08:02am
'Significant disruption' for trains as tube network impacted
Network Rail warned there would be "significant disruption" across England and Wales as it imposes speed restrictions to minimise the risk from heat-related issues such as buckled rails and sagging overhead electric wires.
Passengers have been advised to travel before midday if possible, and carry a water bottle.
On Wednesday morning, Avanti West Coast was the operator with the most disruption as four out of five of its services were cancelled or more than 30 minutes late.
Great Western Railway issued a plea for its services to be used for "essential travel only" on Wednesday and Thursday.
It said speed restrictions mean it will be forced to run fewer services than usual and journey times will be extended.
It is also running fewer trains than normal between London Paddington and Reading because Network Rail is not moving some points - pieces of metal that enable trains to change tracks - on the route to cut the risk of failures, which are more likely in high temperatures.
Meanwhile, the tube network has started to experience delays.
On Wednesday morning, Transport for London (TfL) said there were delays on the Victoria, Mildmay and Central lines as a result of cancellations and running a reduced service because of the hot weather.
There are also delays and part suspensions on the Bakerloo line.
A woman cools off in a Victoria line station - Dinendra Haria/LNP
07:45am
Hundreds of schools closed as heatwave takes hold
Hundreds of schools across the country have closed as a result of the latest heatwave.
Primaries, secondaries and nurseries across England have been shutting since the first day of heat on Monday.
The extreme temperatures forecast on Wednesday and Thursday has seen many schools already announce closure or half-days, with pupils to continue to study at home.
Over 170 schools in Somerset will be fully closed on Wednesday and Thursday, according to Somerset Council.
More than 100 schools in Buckinghamshire and Gloucestershire will also be closing their doors in order to protect their pupils, according to council data.
Children at some schools have been told they can wear PE kit rather than full school uniform, which can involve long trousers and blazers.
07:23am
Commuters told to 'expect disruption' as trains run at reduced speeds
Transport bosses have urged people to avoid travelling on Wednesday and Thursday and are warning those that do to "prepare for a disrupted journey".
South Eastern Railway has already urged its customers to only travel if "absolutely necessary" with extreme heat set to affect services across Kent and south-east London.
On Wednesday morning, National Rail warned of disruption to Gatwick Express, Great Northern, Southern and Thameslink services until Friday.
Bosses warned commuters to "expect disruption" across some routes and that trains would be operating at reduced speeds "for safety reasons".
Avanti West Coast said it planned to run fewer services than usual between Tuesday and Thursday, and that there was "a risk of further disruption".
And Chiltern Railways said it had axed more than half its services until Friday "to ensure the safe operation of the railway".
Eurostar has cancelled four trains planned to run between London and Paris on Wednesday and Thursday "due to expected adverse weather".
07:02am
Red health alerts now active
The UK Health Security Agency's (UKHSA) red heat health alerts came into force at 1am this morning.
They cover the East of England, East Midlands, London, the South East, the South West and the West Midlands, and mean "adverse temperatures are likely to impact on the health and wellbeing of the population".
Amber health alerts have also been issued for the North East, North West and Yorkshire and the Humber.
They will remain in place until 11pm on Thursday.
On Tuesday the highest temperature logged was 34.6C in Wisley, Surrey, according to the Met Office.
Temperatures could reach up to 40C, the Met Office has warned - Adam Davy
06:54am
'Tropical night' for many
Good morning and welcome to our coverage of today's weather which could bring record-breaking highs of 40C.
On Wednesday morning, people across Britain are waking to temperatures which did not drop below 23C overnight.
Swathes of the country were left sweltering in the hot temperatures, which made it a tropical night.
The Met Office defines this as a night when the temperature does not fall below 20C.
The weather service said recent studies show that the UK is now seeing more frequent occurrences of these events, particularly during heatwaves such as these.
Try full access to The Telegraph free today. Unlock their award-winning website and essential news app, plus useful tools and expert guides for your money, health and holidays.[3]
References
- ^ Read the full story here. (www.telegraph.co.uk)
- ^ Read the full story here. (www.telegraph.co.uk)
- ^ Try full access to The Telegraph free today.
Unlock their award-winning website and essential news app, plus useful tools and expert guides for your money, health and holidays.
(www.telegraph.co.uk)