Commuters have been warned they may struggle to get into the office due to a number of train services being cancelled by the extreme weather we're all enduring.

Southeastern announced earlier this week that it would run revised routes across its whole network on Thursday (July 25) as temperatures are predicted to soar to nearly 40C.

Trains that do run will be travelling at restricted speeds due to fears the tracks could "buckle".

The advice given was to avoid travelling altogether, or, if it's essential, to expect a packed and slower journey into the capital.

A Southeastern spokesperson said: "We strongly advise passengers to avoid travelling, or re-time journeys to when trains are less busy.

"If you’re planning to travel with us today, please allow extra time for your journey and check before you travel to make sure your train is running.

There are fears the tracks could buckle in the heat


Elsewhere, Greater Anglia has been forced to cancel services due to the heat.

Follow our live blog below for the latest updates.

Kew Gardens joint highest temp so far in UK

Previous 10 hottest days on record

The Met Office has listed other record-breaking summer days.

Temperature reaches 38.5 degrees in Croydon

The temperature in Shirley is creeping closer to breaking the record for hottest day ever.

Police called to Brockwell Lido

Police were called to Brockwell Lido this afternoon after reports of overcrowding and queue jumping.

Officially the hottest July day in London ever

Temperatures recorded at Heathrow broke the previous July record.

Additional delays on Greater Anglia due to 'overheard wire problems'

As if the heat wasn't causing enough havoc.

Ice lolly on London Bridge took under 14 minutes to melt

To test how hot it is, MyLondon sent one of our reporters to time how long it would take an ice lolly to melt on London Bridge - watch the video back here.

Over 35C recorded at Heathrow Airport

It's lunchtime and London is already baking.

34C recorded at Kew Gardens

BBC weather have reported that a temperature of 34C has been recorded at Kew Gardens.

Effect of 'emergency speed restrictions' on LNER

LNER will be running a reduced service due to emergency speed restrictions in place between Peterborough and London Kings Cross.

Limited rail replacement transport is running between Grantham, Newark and Retford.

Stansted Express 'less frequent'

Stansted Express services will be operating less frequently than normal.

Holiday-makers are advised to allow more time for your journey to the airport.

'Severely reduced train service' on Greater Anglia

There will be a severely reduced train service on some routes in the afternoon and evening.

Customers are advised not to travel unless absolutely necessary.

Overground trains 'revised' thanks to the heat

London Overground are running a revised service on their North London routes.

On West Anglia routes a reduced service will operate, and no trains will call at Cheshunt.

Across the rest of the London Overground network increased journey times can be expected.

You may use your tickets on Greater Anglia, Great Northern, London Underground and TfL Rail services.

Reduced service between London and Cardiff until the evening

A reduced service will be in operation between Cardiff Central and London Paddington until 8pm tonight.

Delays and cancellations on Gatwick Express, Great Northern, Southern and Thameslink

Speed restrictions may cause delays and cancellations to journeys across the whole Gatwick Express, Great Northern, Southern and Thameslink networks until the end of the day, according to a spokesperson.

South Western Railway 'running normally' at the moment

A spokesperson for South Western Railway has confirmed they are "running normally at the moment".

However, they added: "There may be speed restrictions later today once the tracks get a lot warmer."

What a buckled track can do to a train

This gif, posted to Twitter in response to questions about the reduced train speeds, shows what happens when a train goes over a buckled track.

Not all trains air-conditioned

Newer Southeastern trains are air-conditioned but not all of them.

Train carriages halved

A number of trains to and from Charing Cross and Cannon Street are having their number of carriages halved from eight to four.

This should make overcrowding even more of an issue.

Disruption should end tomorrow

Southeastern have confirmed they expect the trains to go back to normal tomorrow (Friday, July 26) when temperatures fall.

A spokesperson added: "If you have a ticket dated Thursday 25 July, you can use it on Friday 26 July, but normal ticket restrictions will be in place."

Why are the services reduced?

A Southeastern spokesperson explained: "Rails are made with a continuous weld of metal in the UK, this means that in extreme heat they can expand and contract.

"As a result we have speed restrictions and fewers services running - lower speeds means lower capacity to accomodate trains, sadly."

What we know so far

Welcome to our live blog of today's morning rush hour.

Here's what we know so far:

  • Commuters are being warned to work from home if possible or to leave extra times for their journeys due to the extreme weather
  • Southeastern trains will have to run at restricted speeds to avoid tracks buckling in the heat
  • This means many services will be cancelled