Yorkshire escaped the worst of the weather as the sunny spell gave way to torrential rain and thundery showers.
Localised flooding was reported in several places on the road between Shipley and Baildon, near Bradford, on Tuesday afternoon and evening.
Hollins Hill, near Guiseley, was said to be “impassable” in the afternoon, and Network Rail said trains were unable to stop at Baildon because of flooding.
A landslip nearby has meant the cancellation of all trains between Bradford and Ilkley throughout Wednesday and “until further notice”.
In the South East, flash flooding saw people rescued from submerged cars and hundreds of calls made to emergency services.
Some 35mm of rain was logged in an hour in south London.
London Fire Brigade said it had received more than 100 flood-related calls, and had attended incidents thought to have been caused by lightning, including trees, hoardings and telegraph poles being set alight.
Two people were helped from their cars and another had to be rescued by fire crews after three vehicles became submerged in two metres of water on Manor Road in Wallington at around 2.21pm.
Met Office forecaster Tom Crocker said Yorkshire got off “relatively lightly”, today with one or two showers over the North York Moors near the coast in the afternoon.
RAF Leeming, near Northallerton, reached a temperature of 26.1C, the third highest in England.
Temperatures will cooling off Wednesday, Mr Crocker said.
He said: “It looks like the wind will be picking up a bit and there will be a bit more of a breeze.
“The maximum temperature will be down a few degrees. York should be 20 to 22 degrees – and closer to the coast Scarborough will be 14 to 15.”
By Friday and the weekend the weather is expected to turn a bit more unsettled and cooler, with temperatures around average for the time of year.
Early mist and cloud will soon lift from most places, but may persist near some coasts, where it remains cool. Otherwise warm sunny spells are expected, and most places should remain dry. However the odd shower cannot be ruled out. Maximum Temperature 21 °C.
Cloud will again spread inland from the North Sea, with some mist and fog possible across coastal spots. Western parts will have the best chance of staying clear. Minimum Temperature 11 °C.
Another warm and often sunny day is expected, once early cloud clears. It will remain dry for most, with only a slight risk of one or two afternoon showers. Maximum Temperature 22 °C.
Outlook for Friday to Sunday:
Turning cloudy Friday with outbreaks of showery rain possible, perhaps heavy. Remaining cloudy Saturday with further rain or showers. Band of rain early Sunday, clearing to sunshine and showers later