
Britain has woken up to flash flooding, thunder and lightning as stormy weather lashes much of the country – dumping almost half a month's rain in a few hours and bringing an abrupt end to the September heatwave.

Roads and properties have been hit by severe flooding in parts of central London, Hampshire, Oxfordshire, Surrey, Hertfordshire and Greater London after a band of torrential rain moved in from the Channel overnight.

Dramatic pictures show cars submerged in floodwater, Tube stations flooded and lightning bolts over the capital.

And it may be a miserable journey home after a rainy day in the capital as flooding threatens to give commuters a disappointing start to the weekend.

Delays of up to an hour are affecting trains from London Euston to Milton Keynes after a landslide derailed a train between Watford Junction and Kings Langley, causing major disruption and scores of cancellations for travellers trying to get from London Euston to the Midlands and the North.

Hundreds of passengers were trapped on the two stricken trains for more than four hours this morning.

The delays are expected to last until the end of the day.

Up to two ft of flood water at Didcot Parkway and Newbury stations in Oxfordshire caused travel chaos. The deluge flooded the underpass at Didcot, meaning only one platform could be used.

Lines at Newbury were submerged by the water preventing services from stopping until one platform operated a reduced service in the afternoon.

The bad weather could continue into Saturday, compounding affected areas further, the environment agency warned.

Water submerged stretches of motorway including on the M4 and M25, where two lorries crashed at around 5.20am.

It was hoped the anticlockwise carriageway of the M25 and the M4 at junction eight would be fully open 'before tonight's peak period, unless weather conditions change again,' said a Highways England spokeswoman.

Trains from Paddington and Euston are delayed and passengers trying to catch flights from Heathrow have allegedly been told not to try to get to the airport today, but that their tickets would be valid tomorrow.

The stormy conditions bring a sudden end to the record-breaking heatwave in Britain which saw temperatures climb to 30C again yesterday - making it the third successive September day that temperatures soared that high.

The mercury plummeted by more than 10C overnight as forecasters issued a string of severe weather warnings.

Commuters are now facing transport chaos after the flash flooding caused problems on the nation's roads - including on the M25, M4 and M40 - as well as on the rail network where 'several incidents' are causing delays.

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Fancy a swim: Dramatic pictures from Didcot railway station in Oxfordshire show the ticket barriers and stairwells submerged in murky floodwater after it engulfed the main concourse. One Twitter user warned others to 'abandon' the station

A rather wet morning commute: One person stood outside a rather flooded Didcot Parkway railway station in Oxfordshire today before learning that trains were cancelled or not stopping at the station due to the flash flooding which hit overnight

Wading through the water: One man was forced to walk through deep floodwater as he arrived at the Spar shop at Didcot Parkway railway station in Oxfordshire this morning following flash flooding overnight which saw half a month's rain fall

Where did summer go? Cars are pictured wading through deep floodwater on the M25 in London early this morning (left) while Maidenhead High Street in Berkshire remained underwater overnight as the drains failed to cope with the rainwater

A bad day on the trains: Euston station in London is packed with commuters after a derailment caused by a landslide near Watford caused London Midland and Virgin train services to be either cancelled or delayed at rush-hour this morning

What to do? Commuters were left questioning how they would get to their destination after train services in and out of London Euston (pictured) were heavily disrupted this morning following the derailment of a train caused by a landslide

Delayed, delayed and... delayed: There was disruption to all trains out of London Euston this morning (pictured) after the derailment near Watford. A landslip on the line caused a train to come off the tracks - forcing dozens of cancellations

Nightmare: A train derailed on the Milton Keynes to London Euston line this morning after hitting a landslip near Watford (pictured). The train came off the tracks before being given a 'glancing blow' by an oncoming train shortly after 6am. Workers can be seen assessing the track following the landslip this morning (left), while the train is seen derailed in the tunnel (right)

A landslide and a derailment: This image on the left shows the damage to the London Midlands train after it derailed and hit another train following a landslip near Watford. Passengers still remained trapped on the stricken train this morning (right)

Crikey! This dramatic photograph shows lightning bolts striking over Godalming in Surrey in the early hours of this morning

Out with a bang: There were dramatic thunderstorms in much of southern England overnight including in Surrey (pictured)

Stormy scene: This graphic from Met Desk shows the extent of the rainfall over southern England at around 1.30am overnight

Four people - two drivers and two passengers, one of whom was pregnant - suffered minor injuries in the crash, which saw the 6.19am service from Milton Keynes derail after hitting the landslide just north of Watford Junction.

Another train travelling in the opposite direction 'gave a glancing blow' to the derailed train, Network Rail said.

It left the two London Midland trains 'leaning against one another' as emergency crews desperately worked to evacuate the some 400 passengers stuck on board.

Around 100,000 could be in line for a refund after the dramatic incident on the early morning service.

Any passenger delayed between 30 minutes and one hour on a London Midlands route is eligible to claim 50 per cent of a single ticket or 35 per cent of a return ticket and a proportion of a season ticket.

Virgin Trains automatically refund anyone who booked through their website if they are delayed by more than 30 minutes.

The train operators will not be footing the bill, however.

Owen Johns, spokesman for Network Rail, said: 'Network Rail pays compensation to train operators when delays are caused by infrastructure issues, including weather, landslips, signalling problems and people under trains.

'Although this delay was not caused by Network Rail, anything caused by the weather is a Network Rail issue. We cover delay repayment for anything not caused by the train operators themselves.

'The train companies pay delayed passengers compensation directly but yes, the money comes from us, we pay them back.

'As Network Rail is an external government body, the money does come from the taxpayer.'

Jake Steers, who was on board the first train at the time of the landslide, described his relief that they were inside the tunnel at the time - or 'there would have been casualties'.

FLASH FLOODING CHAOS The following roads and rail services are disrupted by the flash flooding this morning: ROADS M4 - A34 junction with Newbury M40 - Entire Thames Valley area M25 - Greater London TRAINS Milton Keynes Central and London Euston - Major disruption and 60-minute delays due to a derailed train at Watford Junction Woking to London Waterloo - Delays of 30 minutes due to flooding Reading to London Paddington - Lightning has damaged equipment in Slough, causing delays Didcot Parkway, Oxford - Trains not stopping due to flooding Dorchester to Bournemouth - Delays until 11am due to flood damage Stansted Airport to Cambridge and London Liverpool Street to Stratford - Lightning strike to signalling system is causing severe disruption. Abellio Greater Anglia advises people not to travel Advertisement

He said: 'We were going through the tunnel, when the first carriage derailed and it all shuddered and the train shook violently.

'I didn't see the landslide as we were in the tunnel, then we crashed into the oncoming train slightly.

'I couldn't see the landslide just felt it hit us. It's quite worrying as I have been doing that commute for two and a half years. It would have a lot worse had we not been in the tunnel - there would have been casualties had they been going full speed.'

Both of the London Midland trains involved in the incident are 'still in situ', Network Rail said. Workers are assessing the best way to remove them from the tracks.

The passengers were allowed to get off the stricken trains at around 11am - four hours after the initial derailment and collision - and were ferried back to the nearby Kings Langley station in Hertfordshire on a Virgin train which was drafted in to help.

Speaking before they were rescued, passengers told of the their ordeal.

Chris Robertson said: 'Everyone is fine but we are in a tunnel with limited signal. Don't catch a train to Euston today, the line is shut.

'We hit a landslide and derailed clipping an oncoming train. Emergency services have arrived to get us off but are assessing what to do first.'

A Network Rail spokesman said: 'Both trains are still in situ and the rescue train is on route.

'The service that clipped the London Midlands train which derailed was travelling in the opposite direction.'

The incident is causing major delays to services in and out of London Euston with most journeys cancelled and those that are going ahead suffering delays of at least 60 minutes.

Martin Frobisher, route managing director for Network Rail, confirmed the 6.19am train hit a landslip caused by torrential rain, resulting in it leaving the tracks a few miles north of Watford. The train remained upright, he added.

'Engineers are on site and train services are now running through the area but it will be some time before a normal timetable resumes,' he said.

London Midland tweeted: 'Due to derailment this morning, there will be delays and cancellations. Ticket acceptance in place on other train operating companies.'

A spokesman added: 'The 06.19 service from Milton Keynes to Euston derailed just after 7am this morning at a tunnel near Watford Junction.

'It's at the busiest stretch of mixed railway in Europe and we are expecting delays and disruption until at least midday, but possibly longer. It affects London Midlands trains, Virgin and Southern. Services to the midlands, north west and Scotland will be affected.'

There goes the summer: Londoners were forced to change their sunhats for umbrellas as rain hit the capital this afternoon

Not quite the weather for sightseeing: Tourists donned protective waterproof ponchos as they took in the London sights

So much rain: This is a flooded underpass in the town centre of Maidenhead, Berkshire this lunchtime following the downpour

Flooded: The underpass in Maidenhead twon centre in Berkshire was full of floodwater today after the drains failed to cope

This Met Desk graphic shows rain across the country overnight prompting the Environment Agency to issue a string of alerts

Warnings: The Environment Agency has issued a string of flood alerts for much of London and the wider area in the South

Initially, all four lines of the West Cost main line were closed at the scene, but two were reopened at around 8am.

Mr Frobisher added: 'Our priority is to fully reopen the railway as soon as it is safe to do so. A full investigation into what happened will take place.'

Pictures on social media also show severely waterlogged rail stations and roads, including Didcot Parkway, Newbury and Chieveley stations across Oxfordshire - which is causing further misery for rail passengers.

Water can be seen rising up stairwells and partly submerging ticket barriers at Didcot Parkway station.

Turnpike Lane and Manor House stations on the London Underground's Piccadilly line were closed early this morning but re-opened by around 6.30am, Transport for London (TfL) said.

Meanwhile, on the rail network, South West Trains said 'several incidents are disrupting' the network.

A spokesman said: 'A lightning strike has caused substantial damage to certain elements of our signalling equipment on the line which runs between Ascot and Guildford via Aldershot.

'Train services running through these stations may be delayed or revised. Disruption is expected until the end of the day.'

Flooding has also damaged equipment connected to a level crossing between Dorchester and Bournemouth, meaning they have to be manually controlled, with problems and delays set to go on until around 11am.

Rain, rain, go away: Raincoats and umbrellas were the order of the day in London as heavy rain lashed the capital this morning

Where has summer gone? Commuters were forced to dig out their umbrellas this morning as heavy rain lashed the capital

Trying to ease the flooding: Council workers were seen unblocking drains e after downpours in Godalming, Surrey overnight

Roadside flooding: Water is building up on roads across London and Surrey (Godalming, pictured) after heavy rain today

What a show: Lightning tore across the sky over the iconic Tyne Bridge and Swing Bridge on Newcastle Quayside last night

Light up, light up: Lightning bolts are seen striking over Newcastle last night as thunderstorms ripped across the country

A different kind of light show: Lightning over Godalming in Surrey in the early hours as the storm sweeps across the UK

A 'large amount of infrastructure' at Woking has also been damaged by the water - with disruption and delays expected until the end of the day.

Train services are also severely disrupted between Stansted Airport, Cambridge, London Liverpool Street and Stratford.

A severely reduced service will run between Hertford East and London Liverpool Street after a lightning strike hit signalling equipment. Abellio Greater Anglia is now advising passengers not to travel.

A spokesman said: 'Due to the severity of the disruption [we] are advising you not to travel between Cambridge / Hertford East / Stansted Airport London Liverpool Street / Stratford. Your ticket will be valid on this route tomorrow.'

There is also disruption on the London Waterloo to Woking route, due to flooding, and on the Reading to London Paddington line after lightning strikes damaged signalling equipment.

Thames Valley Police said there was also disruption on roads with congestion on the M4 at the A34 junction with Newbury and on the M40 throughout the Thames Valley area.

Shocking video footage also shows a 'river of water' running down the M25 after it was hit by flash flooding. Cars can be seen driving through the foot-deep floodwater after it engulfed the motorway at J21a near Watford.

This Morning TV presenter Philip Schofield was among those who took to Twitter to comment on the loud thunder overnight

Lighting up the nighttime sky: One Twitter user uploaded this dramatic photo of lightning over Windsor at 3.45am overnight

The storm up north: Twitter users shared these photographs of lightning bolts in the sky above Sheffield during the night

Cars submerged as summer draws to an end: The centre of Ruislip Manor, London, was flooded yesterday evening as up to 40mm of rain fell in just an hour during heavy downpours in parts of the UK, which forecasters warn will continue today

Many residents took to Twitter during the night to complain about being kept awake by the stormy conditions – which swept in after yet another day of balmy temperatures in the capital.

TV presenter Philip Schofield was among those awoken by the loud thunderstorm. He wrote: 'Holy CR*P!!! Thunder nearly blew us out of bed!!', alongside a series of 'laughing and thunderbolt emojis'.

Twitter user, Jay Virdee, said: Windsor at 3:45am #thunderstorms #lightning' before sharing a series of lightning bolt pictures. Another added: 'Crazy crazy storm outside right now. It sounds like the end of the world. Never heard anything like it.'

The weather front has sent temperatures tumbling ahead of the weekend, just days after parts of the country baked in 34C (93F) heat. Temperatures already dropped by 10C overnight and are expected to stay around 18C today.

A yellow warning of rain remains in place for much of England during today, rising to amber along a narrow corridor west of London where 'exceptionally heavy, thundery rain' accompanied by hail is expected.

The Environment Agency has also issued a series of flood warnings.

Surrey Fire and Rescue Service said it had been called to reports of a house struck by lightning near Woking, while crews worked to pump water out of flooded premises across the county.

Energy provider SSE said 1,273 homes across Basingstoke, Newbury, Reading and Bournemouth were left without power as a result of lightning.

Fire chiefs advised motorists to avoid driving through flooded roads and turn around as pictures emerged of Maidenhead High Street resembling a swimming pool.

It's raining, it's pouring: Commuters were forced to shield themselves with umbrellas as heavy rain hit Waterloo, London

At least we're dry! Two youngsters managed to keep out of the rain in their double buggy in Wimbledon, south west London

Hello autumn: Commuters across the capital - from Wimbledon (left) to Waterloo Bridge (right) were drenched at rush-hour

Flooding: The Met Office has put a string of severe weather warnings in place and warned some areas could see flash flooding (pictured, Ruislip, London) as the hard ground - after a scorching week - cannot instantly absorb the rain

The end of summer: Up to 40mm of rain fell in a single hour yesterday (pictured, west London) and as much as 40mm is due later today in some areas, which is equivalent to the average monthly rainfall in September of 60-70mm, the Met Office said

Weather warnings: The Met Office has issued yellow-graded weather warnings for much of the country today, and the more sever amber-graded for London (left). Right: This graphic shows some of the lightning strikes over the UK during the night

TRAIN DERAILS AND IS 'HIT BY ANOTHER' AFTER LANDSLIP CAUSES RAIL CHAOS Hundreds of passengers were trapped on a derailed train for more than four hours today after it hit a landslide and derailed – before colliding with another train. Four people – two drivers and two passengers, one of whom is pregnant – were injured when the London Midland train was hit by a landslip and derailed just north of Watford Junction at around 7am. Network Rail said the 6.19am service from Milton Keynes to London Euston came off the tracks and was given a 'glancing blow' by an oncoming train in a 'slow tunnel'. It left the two London Midland trains 'leaning against one another' as emergency crews desperately worked to evacuate the some 400 passengers stuck on board. Landslide: The train derailed just after it entered this tunnel near Watford when part of the nearby bank crashed down onto the track. Network Rail workers are seen at the track assessing the site this morning - as it remains closed to commuters Aftermath: One of the two London Midland trains involved in the incident near Watford this morning. The train was hit by a landslide and derailed, before being struck by another train Rail workers were seen passing bottles of waters to the stricken commuters, many of whom told of their terrifying ordeal at being involved in the derailment. Jake Steers, who was on board the first train at the time of the landslide, described his relief that they were inside the tunnel at the time - or 'there would have been casualties'. He said: 'We were going through the tunnel, when the first carriage derailed and it all shuddered and the train shook violently. 'I didn't see the landslide as we were in the tunnel, then we crashed into the oncoming train slightly. 'I couldn't see the landslide just felt it hit us. It's quite worrying as I have been doing that commute for two-and-a-half years. It would have a lot worse had we not been in the tunnel - there would have been casualties had they been going full speed.' Both of the London Midland trains involved in the incident are 'still in situ', Network Rail said. Workers are assessing the best way to remove them from the tracks. The passengers were allowed to get off the stricken trains at around 11am - four hours after the initial derailment and collision - and were ferried back to the nearby Kings Langley station in Hertfordshire on a Virgin train which was drafted in to help. Workers at the scene of the collision between the two trains just north of Watford junction Martin Frobisher, route managing director for Network Rail, said a train hit a landslip caused by torrential rain, resulting in a small section of the train leaving the tracks a few miles north of Watford. Pictured: The landslip on the track this morning Chris Robertson said: 'Everyone is fine but we are in a tunnel with limited signal. Don't catch a train to Euston today, the line is shut. 'We hit a landslide and derailed clipping an oncoming train. Emergency services have arrived to get us off but are assessing what to do first.' A Network Rail spokesman said: 'Both trains are still in situ and the rescue train is on route. 'The service that clipped the London Midlands train which derailed was travelling in the opposite direction.' The incident is causing major delays to services in and out of London Euston with most journeys cancelled and those that are going ahead suffering delays of at least 60 minutes. Martin Frobisher, route managing director for Network Rail, confirmed the 6.19am train hit a landslip caused by torrential rain, resulting in it leaving the tracks a few miles north of Watford. The train remained upright, he added. 'Engineers are on site and train services are now running through the area but it will be some time before a normal timetable resumes,' he said. Initially, all four lines of the West Cost main line were closed at the scene, but two were reopened at around 8am. Mr Frobisher added: 'Our priority is to fully reopen the railway as soon as it is safe to do so. A full investigation into what happened will take place.' Emergency crews and ambulances were pictured at the scene of the incident. Advertisement

Met Office meteorologist Martin Combe said 1.3inches (32.8mm) of rain had fallen in just three hours in Farnborough, Hampshire - half the 2.75inches (70mm) average for September.

He said: 'The storms are quite slow moving so it means the amounts are starting to build up over time, so we may get higher figures and localised flooding.

'The showers and thunderstorms are going to carry on for quite some time moving slowly north and eastwards, remaining around London through the morning and all afternoon in East Anglia.

'They will eventually clear off to the east, but it will be cool behind them. While it won't be any colder than average it is going to feel a lot cooler than it has been.'

Away from the storms, today will be a relatively cool and fresh day for the rest of the country with some sunshine.

London is expected to see a high of 21C (70F), Cardiff 18C (64F) and Manchester, Glasgow and Belfast 17C (63F).

Saturday and Sunday are expected to be similarly fresh, although a weather front will bring rain for Northern Ireland, Scotland and Wales on Sunday.