A two-day period of unprecedented weather conditions saw Wales set a new provisional heat record of 37.1 ºC in Hawarden, Flintshire, on Monday afternoon, almost two degrees higher than the previous record.
In England, Santon Downham in Suffolk recorded a high of 38.1 ° C, just 0.6 ° C lower than the current UK national record of 38.7 ° C, set in Cambridge in 2019.
Meteorologists forecast highs of 40ºC in Peterborough, Grantham and Doncaster on Tuesday, with a 95 per cent chance of breaking the current record.
Train services were severely disrupted as Network Rail imposed speed restrictions of 20 mph to 90 mph across the country.
The operator said trains were “too late” and cancellations doubled to normal on Monday, with 2,000 services out of 12,800 with more than half an hour delayed or canceled. Another 2,000 were between five and 30 minutes late.
Only 67% of all rail services in the UK arrived within five minutes of the timetable or 10 minutes on long-distance lines, compared to around 90% on a normal day.
Dozens of operators urged people to avoid travel unless it is “absolutely necessary” as they canceled services. Southern Rail, which serves Brighton and the south coast, said trips to the beach “were not essential”.