Torrential rain, thunderstorms, hail, lightning and high winds will cause flooding and travel disruption in Britain this afternoon and evening, forecasters have warned.
The With office has issued a yellow thunderstorm warning for parts of north-west England, Yorkshire, the East Midlands and East Anglia between 2pm and 7pm today.
A second warning for Northumberland, Cumbria and southern Scotland runs from 3pm to midnight, and a third applies to Northern Ireland between 12:00 and 21:00.
Forecasters expect up to 30mm of rain to fall in just a few hours, while lightning, hail and high winds could cause damage to buildings.
Delays and cancellations of train and bus services are possible, along with road spray, as miserable weather plagues the final days of meteorological spring.
People take shelter under an umbrella in the rain in London's Paddington district this morning
A misty view of Lake Windermere in Cumbria this morning as thunderstorms continue
People wear rain ponchos in London's Paddington area today amid the miserable weather
Speaking about today's weather warnings, Met Office spokesman Stephen Dixon said: 'Britain is currently in the midst of uncertain weather.
“It's going to be a little bit variable within the warning areas. A few lightning strikes and travel disruptions are creating an uneasy feeling for today.”
Particularly heavy rain in some areas may cause road closures.
Temperatures are expected to reach a high of 20ºC (68F) in central England today, while a low of 5ºC (41F) is expected in rural Scotland.
It covers cities including Edinburgh, Aberdeen and Dundee, with forecasters warning of up to 20mm of rain in less than an hour.
Highs of 21C (70F) are expected in the south-east of England on Wednesday.
A yellow warning for thunderstorms will come into force again in Scotland tomorrow at 10am and will last until 7pm.
People are being battered by rain on London Bridge this morning as the capital is hit by downpours
People on a dull and damp morning in Dunsden's Oxfordshire countryside today
A woman takes shelter under her coat in the rain in London's Paddington district this morning
A woman walks a dog along the River Thames on a wet morning in Windsor today
The Steam Dreams train Britannia leaves Windsor and Eton Riverside train station this morning
Mr Dixon said: 'The risk of thunderstorms is spreading further north on Wednesday, with a warning in force for much of Scotland. Further south, many will see a continued mix of sunshine and showers.
'That shower theme, with the possibility of some heavier outbreaks, will continue across much of the country on Thursday, although there will also be occasional sunny spells, which can feel quite pleasant if there is no rain.
'A change has been announced for the weekend, with a ridge of high pressure likely to reduce rainfall totals and bring some warm, dry weather for many, although details will become clearer in the coming days.'
It comes after The Sun reported that the Met Office has warned government and transport chiefs of at least 50 days of rain over three months this summer.
Forecasters have estimated that the chance of rain between early June and late August is 50 percent greater than average, the newspaper said – and that it could be the wettest summer since 1912.
But the Met Office told MailOnline today that current signals show the chances of a wet or dry summer are 'fairly balanced', adding: 'Although rain signals are limited, some periods of uncertain weather can be expected .
“As is typical for this time of year, these periods are likely to bring heavy rain and thunderstorms in some regions.”
And the Met Office's official long-term forecast states: 'A continuation of variable, slow-moving weather patterns is likely for much of June, similar to what was observed in May.
'However, with potentially slow-moving weather systems there is still a chance that longer lasting, drier or even wetter periods are also very possible. Temperatures will most likely be around or above normal.”