Britain’s record-breaking heat wave disrupted travel for a third day and firefighters remained on alert Wednesday even as cloudy skies and showers brought relief from the scorching temperatures of recent days.

Forecasters predicted London would reach a high of 26 Celsius (79 Fahrenheit) on Wednesday, down from the record 40.3C (104.4F) set Tuesday at Coningsby in eastern England. Still, the main train line from London to Edinburgh was to remain closed until noon as crews work to repair power lines and signalling equipment damaged by a heat-related fire on Tuesday, according to the London North Eastern Railway.