Train operators are warning that the increased extreme heat warning for Monday (July 18) could cause disruption to its timetable.

The Met Office has issued a red weather warning for parts of the country on Monday and Tuesday, with temperatures forecast to reach as high as 40°C in some areas.

Following the warning Network Rail has assessed the impact of the extreme heat on the railway infrastructure and said it would be introducing speed restrictions to ensure the safe running of trains.

South Western Railway (SWR), which operates train services into and out of Honiton and Axminster, said the speed restrictions will particularly affect our mainline services, with long-distance services to Exeter, Salisbury, Bournemouth, Weymouth, Southampton and Portsmouth most likely to be impacted.

Great Western Railway, (GWR) which operates trains into and out of Exmouth along the Avocet Line, said services are expected to be significantly impacted and those trains that do run will be extremely busy. Journeys will take longer and there is a high likelihood of cancellations, delays and last-minute alterations.

Customers are being advised to only travel if absolutely necessary on Monday and Tuesday. Passengers who choose to travel are being advised to check their journeys and ensure they are well-prepared for the extreme conditions – wearing cool clothes, taking handheld fans and ensuring they have plenty of water to drink.

SWR’s Customer Experience Director, Christian Neill, said: “These unprecedented temperatures will pose a significant challenge to the national railway infrastructure and we’re sorry for the impact they will have on our services on Monday and Tuesday.

“Network Rail is urging customers to only travel if absolutely necessary and anyone who has to travel should expect longer journey times, short-notice cancellations and disruption.

“We are working on a reduced timetable that provides certainty for our customers, but changes are likely to come at relatively short notice, so if you do choose to travel, please check your journey as close to your time of travel as possible.”

To help customers, GWR and SWR are allowing people with tickets for travel on its services on Monday and Tuesday to travel on Wednesday and Thursday instead.