Hail and thunderstorms are due to hit parts of the UK over the weekend as the warm weather meets more unstable conditions.
While most of the country is set for a warm weekend, parts of Wales, northern England and East Anglia will experience “more lively weather”, according to the Met Office.
Meanwhile, the South East will continue to enjoy unseasonably summery conditions through today and tomorrow with Sunday’s London Marathon forecast to be the hottest on record.
The Met Office has warned that isolated heavy showers with thunder and hail will move up from the South West into northern Wales and then northern England later on Saturday.
Thunderstorms are again forecast for East Anglia later on Sunday with the weather agency saying it could issue a rain warning later this weekend.
Afternoon plans? Plenty of warm sunshine across the UK but with some heavy showers in places, bringing the risk of hail and thunder ��️ pic.twitter.com/jYk7kDjh5L— Met Office (@metoffice) April 21, 2018
Mark Wilson, a meteorologist at the Met Office, said: “There will be showers with thunder and hail through the day and into the evening. We are going to have more lively weather in the next 24 hours.
“You do get them (thunder storms) in the summer and that is another outcome of the warm weather meeting unstable conditions”.
The storms come as the country has enjoyed a heatwave this week that has seen temperatures soar 10C (50F) higher than is normally expected for this time of year.
Thursday was the hottest April day for nearly 70 years, with the mercury soaring to 29.1C (84F) in St James' Park in London.
The Met Office said that the parts of the country unaffected by the showers could expect to see more fine weather over the weekend.
Saturday will see the warmest with highs of 24C (75.2F), with Sunday forecast to be cloudier with a highs of 23C (73.4).
The heatwave has prompted the organisers of the London Marathon to urge runners to adjust their goals for the race and carefully think about whether they attempt it in a bulky costume.
Mr Wilson said Sunday was set to break the record for the hottest London Marathon but that there could be some welcome respite for slower runners, with the chance of showers later in the day.
“There will be highs of 23C, that is still very warm and humid for the marathon,” he said. “The warmest was 22.7C (72.86) in 1996.
“It is going to be a warm start to the day and temperatures will climb further. There is also a risk of showers for later in the race for the slightly slower runners.”
The heatwave is due to come to an abrupt halt on Monday with temperatures forecast to fall sharply to more seasonal levels, ushering in a week of cooler weather and scattered April showers.
Mr Wilson added: “Temperatures are mixed (from Monday) and will be about 16-17C (60-62F) so that is a drop of quite few degrees.
“I think people have forgotten it is mid April as it feels very summery at the moment but 17C (62F) is what you’d expect for this time of year.”