Northern England has experienced heavy downpours and flash flooding, leaving commuters facing road closures and delays.
West Yorkshire Fire and Rescue Service said it received 23 flood-related calls between 9am and 11am on Wednesday, of which seven were attended by crews.
The callouts, mainly around Leeds, included three people stuck in vehicles, and one lightning strike damaging a property in Wetherby.
First Bus services in York suffered "severe congestion" after one central A-road was closed due to flooding in the Fishergate area, causing diversions and compounding delays due to extra traffic associated with events at York Racecourse.
A First Bus spokeswoman said: "Most of our services are delayed due to flooding and race day traffic. We would urge customers to keep checking our website and Twitter feed for the latest updates."
North Yorkshire Fire and Rescue Service also warned the public of the dangers of driving through standing water, and asked people to take care following reports of flooding in Scarborough.
The Met Office said some areas had had as much as 40mm of rain on Wednesday morning, but the worst had passed.
Spokesman Oli Claydon said the heavy, thundery downpours were the result of weather systems related to those affecting Northern Ireland on Tuesday, where emergency services responded to 60 flooding instances between 7pm and 11pm.
Mr Claydon said the worst of the downpours were moving east, creating drier conditions for the coming days.
He said: "The flooding would most likely have been due to the intensity of the showers, but the main intensity started coming through around 9 o'clock this morning and is moving east fairly quickly, so it will clear out to the east in the afternoon."
Met Office spokeswoman Nicky Maxey said that early, unverified figures indicated the UK had already had around 96% of the expected rainfall for August, with the potential for more to come.
However, she said the weather systems were generally in keeping with the types of rainfall the UK experiences in summer months.
"It's not particularly unusual to see these heavy bursts.
"The ones which went through Leeds and Northern Ireland overnight were particularly heavy, but it's common for our summer rainfall to fall in a few heavy bursts rather than frontal rain that can last for a few days in the winter."