More hot weather records have been broken on Tuesday, after London reached an unprecedented May temperature of 35C.
Severe travel disruption has been caused in London as services struggle to cope with the heat.
It comes just one day after the previous all-time high was set in Kew Gardens on Monday afternoon, smashing the previous May peak which stood at 32.8C reached in 1922 and 1944.
The expected high for large swathes of southern England and Wales on Tuesday could creep up to 36C, senior Met Office meteorologist Becky Mitchell said.
Those forecasts span the Midlands, the south-east and south-west England, East Anglia, and South Wales.
A yellow weather warning has been issued for thunderstorms across much of England on Tuesday, the Met Office said.
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Yellow weather warning for thunderstorms issued
A yellow weather warning has been issued for thunderstorms across England on Tuesday, the Met Office said.
Isolated storms with lightning, hail and gusty winds could hit large swathes of the country from Bath and Reading to Lincoln and Sheffield.
The Met Office said many areas will stay hot and sunny but there is potential for as much as 30mm of rainfall in the space of an hour in some parts.
The warning is in place between 3pm and 10pm.
Temperatures in London have already reached 30C in some places this morning, and the mercury is set to keep rising.
Parts of the capital will see highs of 34C, and this could even reach as high as 35C.
There is also a slight chance of showers this afternoon.
Temperatures will drop tomorrow but remain in the low 20s by the early hours of Wednesday morning.
Heat records could be broken in London yet again
The record for the hottest May temperature could be broken again today with an expected high of 35C across large swathes of southern England and Wales – which could even creep up to 36C, the Met Office said.
Those forecasts span the Midlands, the South East, South West, East Anglia and South Wales, with many areas, including London, officially in a heatwave.
Thunderstorms could be sparked in the afternoon, which would affect how hot it gets, the Met Office added.
To qualify as a heatwave, temperatures must meet or surpass a specific threshold for three consecutive days.
The highest heatwave threshold in the UK at this time of year is 28C, which applies to London and north of the capital towards Cambridgeshire.
Temperatures will start to gradually decline from the middle of the week but it will still be largely dry with sunny spells.
UK sees 'tropical night' amid heatwave
The UK experienced a “tropical night” on Monday after the country saw its hottest May day on record, which could be broken again on Tuesday with highs of 36C forecast.
Temperatures did not fall below 21.3C on Monday at Kenley Airfield, south London, as the country broke the record for the warmest May night for the second consecutive day, the Met Office said.
The country also recorded its provisional all-time hottest meteorological spring temperature when Kew Gardens in south-west London hit 34.8C on Monday.
The Met Office listed 12 locations where the record was topped on Monday – ranging from Suffolk to Berkshire to Warwickshire – while 97 of its monitoring sites reached or surpassed 30C.
The UK’s previous warmest May night was measured on Sunday, when temperatures did not fall below 19.4C at Kenley Airfield.
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28C and rising
Incredibly, the temperature has already reach 28C parts of London.
The thermometer reached that level at Heathrow at 8am, according to the Met Office.
Heathrow is often hotter that the rest of London due to its huge expanses of heat-absorbing tarmac and concrete.
Disruption on Elizabeth Line
Commuters were given an early warning of expected disruption on Elizabeth line services between London Liverpool Street and Stratford on Tuesday afternoon.
The travel alert came as temperatures in London could on Tuesday breach the new May record of 34.8C set on Monday at Kew Gardens, south west London.
Rail and Tube users are being advised to take water on their journeys.
London bus drivers ‘at the wheel in 40C conditions’
Some London bus drivers are reportedly having to drive in temperatures of around 40C.
The sweltering conditions have been blamed on poorly maintained cooling systems, according to the London Bus Forums.
The high temperatures are said to be exposing some drivers to heat stress, tiredness and loss of concentration.
London Bus Forums reported being sent an image by a driver on Monday May 25, when temperatures hit 34.8C in London, at around 4.10pm, appearing to show a cab temperature above 40C.