Parts of the UK were forecast to be hotter than Hawaii on Friday, but experts have warned of possible heavy rain and thunder, with more changeable weather to come over the bank holiday weekend.

Temperatures could reach 27C in London and East Anglia at the end of the working week, the Met Office said. Yorkshire was a little cooler in the early or mid 20s.

It would make yesterday the warmest day of the year so far and hotter than Honolulu, the capital of Hawaii, where highs of 26C are forecast.

“We’ve got some very warm, humid air coming up from the south,” Met Office meteorologist Simon Partridge said.

The weather is set to get wet over the next few days. (Photo by Ryan Jenkinson/Getty Images)

placeholder image — The weather is set to get wet over the next few days. (Photo by Ryan Jenkinson/Getty Images)

“That means we will see some very warm weather, particularly in the east and the South East, because there we’ll see the best of the sunshine.

“Unfortunately, it doesn’t mean everybody’s going to get a warm, dry, beautiful day.”

Cloud over the central spine of the UK, from Scotland, the Pennines and into the Midlands meant possible heavy rain yesterday. “Certainly the odd rumble of thunder is possible there, particularly over the Midlands,” Mr Partridge said.

Yesterdays highs in London and the South East were to be around 10C higher than averages for the time of year, which are 15 to 17C, the Met Office said.

Weather over the May Day weekend will be “a different story” though, with changeable conditions forecast across the UK.

“The weekend is a bit of a different story, really,” said Mr Partridge.

“There will be some bright spells in there as well on Saturday, but there will also be showers, particularly across northern and western parts of the UK.”

Rain is forecast across the country on Sunday and temperatures will continue to cool towards averages for May.