London Marathon weather: Capital in for ‘thundery showers’ over weekend but Sunday could still be hottest race yet

Londoners are in for “thundery showers” over the weekend as the gloriously hot weather cools slightly – but forecasters have warned Sunday’s marathon could still be the hottest yet.

The capital has seen record temperatures over the past week as the mercury hitting the highest for April in 70 years – sending Londoners out into the sunshine in their droves.

But the “mini heatwave” is due to come to an end – just in time for the weekend – with temperatures to drop to a balmy but decidedly cooler 16C on Saturday.

Runners taking part in the Virgin Giving London Marathon have been warned, however, that it could still be the hottest on record with temperatures predicted to reach at least 22C.

The hottest race on record was in 1996, according to the Met Office, where runners endured temperatures of 22.7C during the 26-mile run.

Met Office forecaster Marco Petagna said: “There is going to be a dry start on Saturday with risks of some low cloud but plenty of sunshine around in the morning and highs of around 26C in London.

“Towards the evening there is chance of thundery showers breaking out but they will fade away by about 5am when the showers should have moved off to the North Sea so it will be dry for the marathon.”

“Sunday will see a rather humid start – around 16C,” he added. “And for the start of the race there will be low clouds.

"As they lift it will be brighter and around 20C by lunchtime. For the late finishers it will get to around 22C.

“The record is 22.7 in 1996 so it is not far off! Later on Sunday we will see come clouds coming in from the West.”

He added that next week is likely to see more of the cooler temperatures but it will still be slightly warmer than is normal around this time of year with the mercury reaching around 17C.

Brits will also be able to enjoy the Lyrid meteor shower over the weekend and the clear skies make for perfect stargazing conditions.

Astronomers said hundreds of meteors with long, glowing tails will streak across the sky in a display that will reach its peak in London early on Sunday morning.

Find out the best way to watch it here.