Families are heading to beaches and beauty spots across Britain today to enjoy the hottest day of the year so far as temperatures hit 32C (90F).
Bosses are braced for workers deciding to have the day off with fears of sickness absence soaring again as it did after big England football games at Euro 2024.
The Met Office said a generally dry day with lots of sunshine will develop into a warm day for many with the heat peaking later in southern England and Wales.
But while the sun set to shine strongly today, people may still need to keep a brolly close at hand – because thunderstorms are expected tomorrow and on Thursday.
Temperatures are forecast to peak in the South East today and tomorrow as Britons continue to bask in the heatwave, but then things look set to change abruptly as storms are predicted to batter most of England and Wales from 12pm tomorrow.
The Met Office has even issued a warning for the South East tomorrow and another for most of England on Thursday, both of which will run between 12pm and midnight, amid severe downpours – with up to 90mm (3.5 inches) of rain falling in 24 hours.
A woman goes for an early morning run at Blackheath Common in South East London today
A dog walker out early this morning next to the River Thames in Windsor, Berkshire, today
A hazy view of Windsor Castle across Dorney Common in Berkshire this morning
Met Office chief meteorologist Frank Saunders said large swathes of the UK will feel the heat up to the middle of the week.
‘Temperatures are likely to peak at around 32C in South East England on Tuesday and Wednesday, with much of the UK experiencing dry, fine and warm conditions in the first half of the week,’ he said.
Alan Price, chief executive at BrightHR, which monitors absence among over a million employees across 50,000 UK companies, added: ‘We see a significant increase in sickness absence due to hot weather.’
While the warmth will carry on for Wednesday, there is a chance of summer thunderstorms in southern areas – with a warning in place for the South East amid an alert for 50mm (2in) of rain in two hours for some areas.
Thursday should develop into a more unsettled day with potentially impactful thunderstorms again. Friday should bring rain, which will move westward.
The UK Health Security Agency has issued yellow heat health warnings for all areas of England, except the North East and North West, until 9am on Friday.
A spectacular sunrise over the Oxfordshire countryside at Dunsden this morning
The sun rises over a misty Bushy Park in South West London this morning ahead of a hot day
The sun rises in Dunsden, Oxfordshire, this morning at the start of another hot day
It warned the expected hot weather may have ‘significant impacts’ on the health and social care sector across the south east and London, with minor impact elsewhere.
Conditions are likely to impact the ‘vulnerable’, such as the elderly and those with multiple health conditions.
The Met Office said a warm snap is considered a heatwave if a location records at least three consecutive days with maximum temperatures exceeding a designated value – 25C (77F) for most of the UK, rising to 28C (82F) in London and its surrounding area, where temperatures are typically higher.
The hottest day of the year so far saw a temperature of 31.9C (89.4F) recorded at St James’s Park in London on July 19.
But while many enjoy the heat, Met Office deputy chief meteorologist David Oliver issued a warning for southern areas to prepare for a wild and wet end to the week.
A Met Office thunderstorm warning in place for tomorrow, running from 12pm until midnight
The Met Office has also issued a thunderstorm warning for Thursday from 12pm until 11.59pm
‘There’s a chance of some thundery showers across some southern areas of England on Wednesday, then on Thursday there is a signal for some potentially very heavy thunderstorms to develop,’ he said.
‘There are still details to confirm during this period, but in any event there is a chance of some impacts on each day, especially Thursday.’
He added: ‘The heaviest showers on Thursday could result in 20-30mm of rain within an hour, with daily totals possibly reaching as high as 90mm if multiple showers impact the same location. Lightning and hail present additional hazards, with disruption likely for some.
‘This is a developing element of the forecast, so it’s important to stay up-to-date with the latest outlook in the coming days.’
The average August rainfall in England is 75mm (2.95 inches) – meaning more than a month’s rain could fall in one day.
The heatwave threshold is met when a location records at least three consecutive days with maximum temperatures exceeding a designated value. This is 25C (77F) for most of the UK, but rises to 28C (82F) in London and its surrounding area, where temperatures are typically higher
The UK Health Security Agency has issued a yellow heat health alert for the South and East of England, the Midlands and Yorkshire and Humber regions – until 9am on Friday
Forecasters said in the thunderstorm warnings for tomorrow and Thursday that there could be road closures, train delays and power cuts.
They also said in Thursday’s warning that there is ‘a small chance that homes and businesses could be flooded’ and cause ‘a danger to life.’
Toolstation reported its sales of outdoor furniture were up 448 per cent compared to the previous week, while sales of cooling fans had risen 207 per cent.
The DIY and trade retailer also saw sales of watering cans rise 31 per cent, and sales of its garden sprinklers and water sprayers range increase 23 per cent.
Meanwhile, Lakeland said sales of its gas pizza oven had risen 72 per cent, its ice cream maker was up 59 per cent and picnic baskets increased 25 per cent.
Also this week, the London Fire Brigade urged parents and carers to explain the risks of jumping into water and open water swimming to children.
Craig Carter, the LFB’s assistant commissioner for prevention and protection, said: ‘It’s a sad statistic that the risk of drowning in England increases as children reach their teenage years, and that teenage boys are the most likely group to accidentally drown.
‘It can be tempting to cool off from the heat by going for a swim. But despite the heat, waterways are still cold enough to put a person into cold water shock which can affect anybody, no matter their fitness.
‘It can cause panic, anxiety, disorientation, and loss of muscular control, which causes a person to gasp for air – inhaling water as a result.’
He urged anyone caught in a dangerous situation to ‘float to live’, which involves tilting your head back and submerging your ears; trying to relax and breathe normally; gently moving your hands to help you stay afloat if you need to; and spread your arms and legs out to improve stability. Once your breathing is under control, you should then call for help or swim to safety.
Mr Carter added that he was urging people not to take disposable barbecues with them to open spaces because they can cause grass fires, especially in hot weather when the ground is dry.
The turnaround in conditions follows a very wet start to July – with East and South East England seeing about a month’s worth of rainfall in just the first week.
And mobile data from the new Virgin Media O2 Business Movers Index revealed a decrease in shopping visits compared to the same time last year – with shopping centre trips down 12 per cent and high street shopping falling 6 per cent.
The firm said this could be a result of only 15 per cent of shoppers being willing to hit the high streets in bad weather. It added that retailers were deploying tactics such as changes to their operations, putting on discounts and hosting special events to get people in.
