Commuters have been advised to avoid travelling on key rail routes in London and the south-east on Thursday as record temperatures threaten to cause tracks to buckle.

Train companies operating services into London from Kent, Sussex, Cambridge and other commuter-belt counties said they would be running fewer trains and imposing speed restrictions. They warned passengers to avoid travelling if possible. LNER, operator of the London-to-Scotland east coast line, also advised customers against travelling.

Netherlands and Belgium record highest ever temperatures Read more

Network Rail said in hot weather tracks can be 20C hotter than the surrounding air temperature, causing the steel rails to expand and buckle under pressure from trains. Tracks are less likely to buckle if trains run more slowly, it said.

Southeastern Trains, which operates services into London from Kent and East Sussex, said it would run significantly fewer services on Thursday to let trains travel more slowly.

As a result, many trains will be much busier than usual and journeys will take longer, Southeastern said. “We strongly advise you to avoid travelling, if you can.”

Southern Trains, which runs routes from Brighton, Cambridge and Gatwick airport into London also warned of delays and advised passengers not to travel. The Gatwick Express, Great Northern, Southern and Thameslink services will all be affected, it said.

Quick guide What is causing Europe's heatwaves? Show Hide Is this a record-breaking heatwave? Temperature records for this time of year have already been broken across much of Europe. The highest ever June temperatures were recorded in the Czech Republic, Slovakia, Austria, Andorra, Luxembourg, Poland and Germany, while France registered an all-time record high of 45.9C. Why is it so hot? The latest heatwave, caused by an “omega block” – a high-pressure pattern that blocks and diverts the jet stream, allowing a mass of hot air to flow up from northern Africa and the Iberian peninsula – follows a similar extreme weather event last month that made it the hottest June on record. Is this heatwave a result of climate breakdown? It is not possible to pin the heatwave definitively on climate change because weather varies naturally. Moreover, the effects of climate change are not simple. For example, heavy rain and cloud across northern Europe is likely to become more common as the buildup of carbon dioxide in the atmosphere causes the jet stream weather system to become fixed in position. However, this year’s weather is certainly in line with the predictions scientists have made of rising temperatures, more heatwaves and prolonged droughts interspersed with periods of heavy flooding. What are the negative impacts of a heatwave? The body’s ability to regulate its own temperature is crucial; babies and older people are less well able to regulate their temperature and should stay in well-ventilated conditions. In the 2003 European heatwave there were about 70,000 excess deaths attributed to the long hot spell. People with underlying illnesses can also have problems, and even those who are healthy can experience difficulty sleeping and discomfort, so people are advised to stay hydrated and wear loose clothing at night. There is also an impact on farmers. While warmth at the right time is crucial for crop growth, excessively high temperatures can inhibit that growth, particularly if they are prolonged. Livestock can also suffer in the heat and need extra care. Fiona Harvey Environment correspondent



Greater Anglia said it would run fewer trains from London Liverpool Street to Norfolk, Suffolk and Essex on Thursday and advised customers to check services before travelling. Services from the Midlands, the north and other regions into London may also be affected.

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The south-east is forecast to be the hottest part of the country as the heatwave reaches its peak with temperatures in London set to hit a record 37C. Rail companies from across the UK were meeting on Wednesday afternoon to agree reductions to the next day’s services.

Transport for London, which operates the London underground and overground rail services, said journeys may take longer than usual on Thursday because of speed restrictions. Like the rail companies, it advised passengers to carry a bottle of water.

Nick King, network services director at Network Rail, said: “We sometimes have to put speed restrictions on to prevent our rails from buckling, which can derail a train and cause huge delays. Passengers should check before they travel, by visiting their train operator’s website or National Rail Enquiries.”