Days of sunshine leading up to the warmest days of the year so far are set to be interrupted by thunderstorms forecast to hit parts of the UK.

A balmy 25.7C was recorded at Heathrow Airport at 2pm on Tuesday, making it the hottest day of 2021 so far – toppling a top temperature set just the day before.

Bank holiday Monday’s maximum temperature was 25.1C in Kinlochewe, Scotland, as sunseekers enjoyed the long weekend and newly restored freedoms following the lifting of many lockdown restrictions.

The mercury is set to climb even higher on Tuesday, with highs of 27C predicted for the first day of meteorological summer, according to the Met Office.

However, thunderstorms are likely across parts of south-west England and southwest Wales on Wednesday, leading the Met Office to issue a yellow weather warning for these areas.

Met Office meteorologist Alex Burkill said: “The thunderstorms could bring lots of lightning, some hail, as well as some heavy rain, and with the half term there is an increased number of tourists in this area.

“The thunderstorms do then push north-eastwards into the Midlands and across more of Wales, but they also ease and break up, so these places will see some showers but they won’t be as intense.”

The thunderstorm warning from 5am to 11am warns that there could be some short-term loss of power and other services, while delays to train services and poor road conditions are possible.

But Mr Burkill said that Wednesday was likely to be hotter than Tuesday, with the possibility of a sizzling 28C or 29C in some areas.

The warm weather has been a welcome break for people following a washout May, which brought heavy downpours and prolonged spells of rain for much of the UK.

Wales experienced the wettest May since records began in 1862, with 245mm of rainfall, topping the previous record of 184mm set in 1967, according to the Met Office.

The UK has seen its fourth highest amount of rainfall on record for the month, with an average of 120mm.

Meanwhile, England had its fifth wettest May on record, and its wettest since 1967, with 111mm of rain.