Tuesday is set to be even hotter than Monday's record breaking heatwave with temperatures soaring to 36C.
The Met Office has warned that sweltering temperatures could reach up to 36C in the south east of England by 2pm on Tuesday - just a day after Britain recorded its hottest ever May day.
A searing 34.8C was recorded in Kew Gardens, south-west London, exceeding the previous hottest May day of 32.8C in 1944 - as well as the bank holiday record of 33.3C in August 2019.
The Met Office said the 34.8C heat is 'exceptional in the UK even in mid summer, let alone in May'.
Up to nine counties saw record breaking temperatures today amid a 'historic' 35C bank holiday heatwave in Britain.
Tens of thousands of Britons flocked to the coast and beauty spots to bask in the blistering heat despite official government guidance to stay out of the sun during the hottest times of the day.
Wales saw its hottest ever temperature in May on Monday evening, with 32.2C recorded at Hawarden Airport in Flintshire. The previous record of 30.6C in Newport stood for 82 years.
Greater London, Surrey, Norfolk and Oxfordshire, saw temperatures soar above 32C - and the Met Office forecasts the mercury could yet climb to 36C tomorrow.
The Met Office has warned that sweltering temperatures could reach up to 36C in the south east of England by 2pm on Tuesday
Tens of thousands of Britons descended on beaches today, including in Bournemouth (pictured)
Tourists and families cool off in the sea at Bournemouth beach
The beach was completely full to the brim on Bank Holiday Monday
People enjoy the hot weather on Bournemouth beach in Dorset
Amber and yellow health alerts remain in place across England, as temperatures continue to soar on what the Met Office has described as an 'unprecedented' heatwave for this time of year.
The warnings came as a man died on the beach in Hastings, East Sussex, following a 'medical incident', and a 15-year-old boy drowned at Swanholme Lakes in Lincoln on Sunday.
Elsewhere, almost 60 people were treated for conditions including heat exhaustion at the Edinburgh Marathon on Sunday and around 500 properties supplied by South East Water, in Sussex and Kent, were hit with outages and low pressure.
On Monday, beaches across the country were full of sunseekers while others descended on lidos and parks as they made the most of the final day of a scorching weekend.
The record high temperature of 34.8C was recorded in Kew Gardens at around 4pm, beating the previous records of 34C at Heathrow Airport and Bushy Park, Teddington, earlier on Monday.
The previous hottest ever May day of 32.8C was recorded in Camden Square, north London, on May 22, 1922, and in Horsham, Tunbridge Wells and Regent's Park on May 29 1944.
In a record-breaking spell of hot weather, temperatures soared to 30.9C in Wales, 25.5C in Scotland and 24.6C in Northern Ireland.
Tomorrow is expected to be another extremely hot day, with a peak of 35C expected in London, the Home Counties and Cambridgeshire.
The blistering heat will continue through the week, with highs of 31C forecast for Wednesday, 30C on Thursday, 27C on Friday and 28C on Saturday.
Tom Morgan, a Met Office meteorologist, said: 'We rarely see temperatures above 35C, even in the summer months, so to see temperatures getting close to 35C in May is, as I say, pretty historic.'
The Met Office said the warm spell has been driven by the development of high pressure over the country that caused air to sink, compress and heat.
Scientists say the record-breaking heat is a stark reminder of how the climate crisis is impacting lives in the UK.
More heatwaves are expected across the summer due to the developing 'super El Niño'.
The phenomenon, which supercharges weather events such as making heatwaves hotter, is predicted to hit in 2027 but it is expected to begin emerging this summer.
Families flock to Bournemouth beach on the bank holiday Monday amid searing temperatures
Tourists gather in sweltering temperatures to watch the Changing of The Guard, outside Buckingham Palace
Brits were seen lounging on Bournemouth beach in Dorset early on Bank Holiday Monday
A man tragically died in Hastings, East Sussex, on Sunday. Police said they were called to a 'medical incident' on the beach
People are seen soaking up the sun while sitting on Jubilee Beach in Southend on Monday
The Essex seaside setting was crammed with visitors making the most of the sunny conditions
Youngsters were seen taking a dip in the sea in Southend on Bank Holiday Monday
An aerial view of visitors enjoying the hot weather at Bournemouth beach on Monday
Competitors take part in the annual Cooper's Hill cheese rolling event on Monday
Tom Kopke, 24, winner of the first men's downhill race during the annual cheese rolling at Cooper's Hill in Brockworth, Gloucestershire
A guard tries to calm down an agitated horse who refuses to stand in the arch at Horse Guards Building in the scorching sunshine as temperatures soar in the capital
Mr Morgan said overnight temperatures could also lead to further records being broken, making it 'uncomfortable for sleeping'.
With temperatures predicted to soar to a 'historic' 35C today, the UKHSA and the NHS warned Britons to keep out of the sun - especially at the hottest time of the day, between 11am and 3pm.
Temperatures did not fall below 19.4C at Kenley Airfield in south London overnight, provisionally breaking the previous May record of 18.9C set back in 1944.
Parts of the country were as hot as the Mediterranean on Sunday, with the UK enjoying its hottest May day for at least 79 years with a high of 32.3C at Kew Gardens in south-west London.
The Met Office said eight regions officially entered heatwave conditions on Sunday after three days at or above the temperature threshold.
They were Heathrow in Greater London, Benson in Oxfordshire, Brooms Barn in Suffolk, High Beech in Essex, Kew Gardens in London, Northolt in London, Santon Downham in Suffolk and Writtle in Essex.
On Monday, thousands of tourists descended on the famous beauty spot of Durdle Door after the beach reopened for the first time in three months.
The iconic stone arch in Dorset can only be accessed by 143 wooden steps built into the steep 200ft cliff. Access was shut off for safety reasons in late February after winter storms destroyed the bottom 40 steps.
Sunseekers and families have been packing out beaches and parks across the Bank Holiday.
Thousands were pictured luxuriating in the heat at seafronts including in Brighton, Bournemouth, Lyme Regis and Devon - while many more swarmed at local lidos and nearby rivers over the three-day weekend.
Others braved the sweltering conditions to watch the annual cheese rolling at Cooper's Hill in Brockworth, Gloucestershire.
German YouTuber Tom Kopke won the first downhill men's race. While 11-year-old boy William, the son of 23-time champion and Guinness World Record winner Chris Anderson, won the first children's uphill race.
Meanwhile, revellers did not let the heat stop them partying at Bank Holiday festivals over the weekend - including the BBC Radio 1's Big Weekend at Herrington Country Park, Sunderland, as well as star-studded events in Brockwell Park, south London.
However, tragedy struck when a man died on a packed beach in Hastings yesterday. Emergency services including an air ambulance scrambled to the scene after a 'medical incident'.
The man tragically passed away at the scene, on the beach near Warrior Square in St Leonards.
A spokesperson for Sussex Police said: 'Emergency services responded to a medical incident on the beach near Warrior Square, St Leonards, following concerns for a man's welfare.
'Officers assisted with the emergency response after the incident was reported at 11am on 24 May. Sadly, despite the best efforts of paramedics, the man was declared deceased at the scene.
'His next of kin have been informed and our thoughts are with them at this difficult time. There were no suspicious circumstances and a report will be prepared for HM Coroner.'
Elsewhere, in Lincoln, the body of 15-year-old Declan Sawyer was recovered at Swanholme Lakes after he disappeared while swimming with a group of friends during the heatwave.
A Lincolnshire Police spokesman said: 'We can update that our dive team have sadly found a body in the water at Swanholme Lakes, Lincoln. With agreement from the family, we can share that the boy who died is 15-year-old Declan Sawyer.
'Our thoughts are with his family, and we send our condolences at this incredibly difficult time. This is such a sad incident that will no doubt also affect many of Declan's friends and the local community as well.'
Authorities have warned about the dangers of swimming in reservoirs and lakes over the weekend.
About 500 properties supplied by South East Water have been hit by issues including outages and low pressure as temperatures soar.
The water firm apologised after it had to hand out bottled water to some of its customers in Kent and Sussex.
A total of 250 properties in three Kent villages were suffering intermittent water outages or low pressure on Monday.
A burst water main in Eastbourne, East Sussex, affected 168 properties, while 64 customers suffered from issues with booster pumps at Radfall near Broomfield Gate in Whitstable, Kent.
There were also 'ongoing water supply problems' for fewer than 20 properties on higher ground in the Ulcombe area of Kent.
South East Water incident manager Steve Benton said in a statement on Monday: 'We're sorry to all impacted customers for the disruption caused.
'We know water supply issues during hot weather are deeply frustrating and incredibly inconvenient and we are working as quickly and safely as possible to resolve them.'
He added: 'As a result of the recent hot weather, we're seeing increased demand across our network and we're having to pump far more drinking water than usual.
'We're working hard to maintain supplies to customers across our network as the hot weather and increased demand for drinking water continues.
'Some customers on higher ground may, however, experience low water pressure or intermittent supply at peak times.'
In Scotland, almost 60 people were treated for heat exhaustion and other afflictions during the Edinburgh Marathon on Sunday, due to temperatures which topped 23C.
Thousands braved the sweltering Edinburgh sun in pursuit of a place among the exalted group of runners to have completed a full marathon, but more than a dozen ended up in hospital because of the exertion.
The Scottish Ambulance Service (SAS) said that 16 people in total were transported to hospital on Sunday, with dozens more - including members of the public - receiving medical assistance.
A spokesperson for SAS said that people were treated for 'a range of conditions', including heat exhaustion, along the route, which ran from Potterrow, through Aberlady, and concluded in Musselburgh.
SAS personnel were able to 'proactively' identify people suffering and offer assistance.
In a statement, they said: 'Due to the higher temperatures experienced over the weekend, we responded to and treated an increased number of runners presenting with a range of conditions, including heat exhaustion throughout the route.
'We attended to 59 patients with 14 patients transported to Edinburgh Royal Infirmary and 2 patients transported to Western General Hospital.
'We had staff based at the marathon and placed along the route as part of the event plan who worked proactively to identify and manage anyone needing medical assistance.'
A woman braves the searing temperatures for a morning run on Wimbledon Common
Families seen going for dips in the sea in Bournemouth on the scorching Bank Holiday Monday
A swimmer and dog enjoy the cool sea temperatures off the beach in Brighton
People relax in the sunshine on the beach in Brighton, on the south coast of England
Visitors queue for sunbeds at Bournemouth beach
Emergency crews scrambled to the beach in Hastings yesterday after the death of a man
Grimsby Town and Salford City fans baked in the heat at Wembley as the two sides contested the League Two Play-off final
Police patrol Bournemouth beach after scenes of chaos over the weekend
A wedding couple pose for pictures in the sunshine on Westminster Bridge in central London
Tourists were seen enjoying the conditions on Bank Holiday Monday on Westminster Bridge
People were also pictured along the Kennet and Avon Canal in Woolhampton, Berkshire
Beachgoers settle for the day in their spot by the sea at Gyllyngvase Beach, Falmouth
Elsewhere, there were scenes of chaos on Saturday as youths were pictured inhaling so-called 'hippy crack' on Bournemouth beach while a girl was carried away on a stretcher.
Later on in the afternoon, six officers went onto the beach and apprehended a young man for unknown reasons before escorting him away.
He apparently resisted arrest all the way to the promenade before being placed in a police van as bystanders watched on.
Police also had to intervene when a group of girls brawled near the Red Arrows simulator.
One of the girls appeared to have her hands around another female's neck before the skirmish was diffused.
Although Monday is set to be hot for many parts of England, north-west Scotland will be breezier and damper with thicker clouds.
Saturday was the first time this year that the UK had passed 30C and Sunday saw the hottest recorded May temperature since 1947.
The UKHSA issued its first amber health alert of 2026 on Friday, warning that there is a risk of a significant impact across health and social care services.
The alert will remain in place until Wednesday.
The heat is considered to be dangerous for some vulnerable groups including older adults as their bodies struggle to regulate temperature.
Swimmers cool off in the sky pool in Nine Elms, south London
People enjoy the hot weather on Primrose Hill, north London, as the UK has recorded its all-time hottest May temperature
A father and his sons ride their bikes on the North Yorkshire Moors
Visitors escape crowded beaches and cool off in Hutton Beck as it runs through Hutton le Hole
People read books in the sunshine in Greenwich Park as record temperatures hit the UK
Tourists shelter with an umbrella at an ice cream van on Westminster Bridge
Animal lovers take part in Alpaca yoga at Hope Farm, Dorset
A man tells his dog to go fetch at water fountains in Battersea Park, south west London
Londoners flocked to Parliament Hill lido to enjoy the scorching heatwave over the weekend
Tourists enjoy a river cruise along the Thames in London
A man floats down the River Great Stour in Fordwich, Kent
Dr Anya Gopfert, Consultant in Health Protection at UKHSA, said: 'We know that even moderate heat can lead to serious health problems, especially for older people and those with certain health conditions, so it's important that everyone takes simple precautions while enjoying the warm weather over the coming days.
'If you have friends, family or neighbours who are more vulnerable, it is important to check in on them and ensure they are aware of the forecasts and are following the necessary advice.'
Age UK recommends staying inside during the hottest hours of the day, between 11am and 3pm, and having regular cold baths or showers.
Age UK charity director Caroline Abrahams said: 'We can all help older people stay safe during periods of hot weather by checking in on older relatives, friends and neighbours to see if they need anything or are struggling with the heat.
'Offering to pick up shopping or medication, or even lending a fan, can make a real difference.'