The risk that rail tracks will buckle in the heat is disrupting train services between Cardiff Central and London Paddington. The UK could have its hottest day on record, with temperatures of up to 39C (102.2F) forecast in southern England, but it is likely to reach just 30C in Wales. Great Western has cancelled trains between London, Cardiff and Swansea. Speed restrictions are in place to protect tracks, Network Rail (NR) said. In such weather conditions, the track can get up to 20 degrees hotter than the air temperature, said NR, which manages the rail network infrastructure.
Network bosses have cancelled trains because of concerns the hot weather will buckle tracks.