The mercury could hit 40C for the first time in the UK, and meteorologists expect the record London temperature of 38.1C at Heathrow Airport in 2003 to be exceeded.
While mayor Sadiq Khan also said Londoners would have to make substantial changes to their routines, and issued a high air pollution alert.
Follow the LondonWorld live blog throughout Monday and Tuesday as our team brings the latest weather and travel updates during the sweltering weather.
London heatwave live
Dozens of firefighters are battling two blazes in the Shirley Hills woodland in Croydon, south London, my colleague Jessica Frank-Keyes reports.
Two grass fires have broken out in the forested area as the heatwave continues to scorch the city, with temperatures reaching record highs of 40.2C in the capital.
Eight fire engines and around 60 firefighters are currently dealing with a fire in the woodlands on Oaks Road in Croydon, after the brigade was called at 12.07pm.
While another four fire engines are also dealing with a grass fire on Chapel View in South Croydon, where around one hectare of woodland and undergrowth is currently alight.
Firefighters were called to the scene just 13 minutes later at 12.20pm.
The Avanti West Coast train operator, which runs services from London Euston to Manchester and the North West has cancelled all services for the rest of the day.
It said: “Due to the extreme heat causing multiple incidents across the network, all Avanti West Coast services have now been withdrawn for the rest of today - Tuesday 19 July.”
It urged people not to come to stations.
It said services would likely be affected tomorrow (Wednesday) as well.
Customers with tickets can use them tomorrow or Thursday, or claim a refund.
Firefighters are currently dealing with at least 10 major fires across London, as the LFB declared a major incident.
- 30 fire engines dealing with a grass fire on Pea Lane in Upminster.
- 15 fire engines tackling a fire on The Green in Wennington.
- 12 fire engines tackling a fire involving garden fencing and trees on Uxbridge Road in Pinner.
- 10 fire engines tackling a restaurant fire on Green Lanes in Southgate.
- Eight fire engines tackling a grass fire on Oaks Road in Croydon.
- Eight fire engines tackling a grass fire on Ballards Road in Dagenham.
- Eight fire engines tackling a fire on The Broadway in Wembley.
- Six fire engines tackling a grass fire on Sunningfields Crescent in Hendon.
- Four fire engines tackling a grass fire on Chapel View in Croydon.
- Four fire engines tackling a fire on Sidcup Road in Eltham.
Prof Stephen Belcher, from the Met Office, has said it was impossible for UK temperatures to reach 40C without the impact of climate change.
On the record-breaking day, he commented: “Well I wasn’t expecting to see this in my career, but the UK has just exceeded 40C for the first time.
“In some ways 40C is an arbitrary figure because we know see the impact of heatwaves at lower temperatures.
“But for me, it’s a real reminder that the climate has changed and it will continue to change.
“Research conducted here at the Met Office has demonstrated that it is virtually impossible for the UK to experience 40C in an undisrupted climate.
“But climate change driven by greenhouse gases has made these extreme temperatures possible, and we’re actually seeing that possibility now.”
And the boffin warned that if we continue releasing emissions the mercury could hit 40C every three years.
“We’re already committed to a level of warming, and these temperatures will get more extreme in the future,” he said.
“The only way we can stabilise the climate is by achieving net zero, and of course the UK has made some great strides in that direction.
“But we want to stabilise the climate to a safe level and that means achieving net zero soon.”
Firefighters and Network Rail engineers are at the scene near Pinner, in Harrow, battling the blaze.
While a fallen tree is also affecting power lines along the route to London Euston.
It comes as the UK sees record-breaking temperatures of above 40C as the UK blisters in a punishing heatwave.
The capital’s fire service has declared a major incident, as firefighters rush to extinguish blazes in Croydon, Havering and Dartford this afternoon (Tuesday, July 19).
“This is due to a fallen tree and our engineering teams are on their way. Advice is still not to travel from London.”
They added: “There is a fire on this site and we have had to shut off the power so the fire service can put it out.
“Our engineers will then assess the damage to the power lines.
“Expect reduced services to be cancelled or delayed until we can fix the problem.
“Engineers and the fire service are on site in Hatch End to put out the fire and start work on repairing the overhead lines.”
Matthew Goodwin-Freeman, councillor for Hatch End, told LondonWorld he was at the scene and had spoken to the incident commander.
Eight fire engines attended the blaze which was under control in an hour.
“Crews will remain on scene to deal with any hotspots,” he said.
“A tree has fallen on the rail lines and caused damage to overhead power lines.
The alert was issued on Tuesday and will be active between 1pm and 9pm tomorrow (Wednesday).
“Heavy showers and thunderstorms are expected to develop across central, southern and eastern parts of England on Wednesday afternoon,” said the Met Office on its official website on Tuesday afternoon.
“Whilst most places will see only small amounts of rain there is a chance of some isolated heavy downpours and lightning.
“Where these occur a few sites could see 20-30 mm in an hour and 50 mm in three hours.”
What to expect?
- Where flooding or lightning strikes occur, there is a chance of delays and some cancellations to train and bus services.
- Spray and sudden flooding could lead to difficult driving conditions and some road closures.
- There is a slight chance that power cuts could occur and other services to some homes and businesses could be lost.
An exceptionally hot day will develop after a very warm start for many, with lengthy periods of strong sunshine and a southerly wind. The sunshine may turn hazier in the west later, with isolated gusty showers or thunderstorms developing. Maximum temperature 40 °C.
Another warm night, with isolated showers or thunderstorms gradually clearing into the North Sea. Probably becoming cloudier from the west overnight, perhaps with the odd spot of rain later. Minimum temperature 17 °C.
Still very warm, but cloudier overall with outbreaks of rain. Heavier, more showery bursts may develop in places later, potentially thundery at times. Breezier than recently, and gusty around showers. Maximum temperature 28 °C.
Outlook for Thursday to Saturday:
More seasonable temperatures are expected through this period. Sunny spells and showers Thursday may give way to more widespread thundery showers Friday. Probably warmer again Saturday, with sunshine and showers.
London Fire Brigade calls for ‘urgent’ ban on disposable barbecues amid record-breaking 40C temperatures
Fire have been breaking out across the capital, and the London Fire Brigade has declared a “major incident”.
Now fire commissioner Andy Roe has called for a ban on disposable barbecues in parks and open spaces.
It comes after the fire service says it has attended more than 1,000 grass and open land fires since the start of June - just under seven weeks ago - making it more than 20.4 a day.
Andy Roe, chief of the fire service, issued a London-wide safety warning and said: “With no end to the hot weather in sight, I am deeply concerned the unprecedented scale of these fires is set to continue, putting lives at risk and devastating green spaces around the capital.
“The London Fire Brigade (LFB) has been issuing warnings and safety advice to Londoners throughout the summer, but people are continuing to behave carelessly and recklessly.
“I am now calling for a temporary ban on the use of barbecues in all public parks and open spaces and I’m asking for your help to keep people safe.”
The London Fire Brigade has declared a “major incident” due to the number of blazes which have broken out amid record temperatures.
Almost 200 firefighters are currently tackling a blaze in a cornfield next to the M25, while 100 other firefighters are attempting to contain a grass fire which has spread to buildings in Wennington.
Mayor of London Sadiq Khan said: “This is critical: the London Fire Brigade is under immense pressure. Please be safe.”
The mayor urged Londoners to:
- Don’t BBQ on grass or balconies
- Don’t leave broken bottles or glass on the grass (it can start fires)
- Dispose of cigarettes safely
- Report a fire as soon as you see one
The Met Office provisionally recorded the sweltering temperature at 12.50pm, which is the first time Britain has registered the mercury hitting 40C.
The previous hottest day on record in the capital was on August 11 2003 of 38.1C at Heathrow Airport.
Oxford Circus Tube station has been evacuated after smoke was found pouring from an escalator, the fire service has said.
Firefighters were called to reports of smoke issuing from an escalator machine room on the northbound Victoria Line at Oxford Circus.
The station was closed while emergency services responded to the fire alert.
Transport for London (TfL) said tickets were being accepted on London buses.
At 11.15am, a fire service spokesperson said: “The incident at Oxford Circus is now over for firefighters.
“Crews investigated reports of smoke issuing which is believed to have been caused by escalator brake pads overheating.
“There was no fire apparent.
“Around 14 members of staff and 2,000 members of the public were evacuated.”