Britain could enjoy the hottest day of the year so far today as temperatures soar to 33C (91F) after some areas entered an official heatwave for the first time since June.
The UK Health Security Agency has upgraded its heat health alert to amber across every region of England apart from the North East, where a yellow alert is in place.
The six-day alert, which began yesterday and will run until Sunday night, warns of higher death rates and ‘significant impacts’ on vulnerable people and the NHS.
But Britons will flock to parks and beaches today to enjoy the warmth as the mercury could top the current 2023 high of 32.2C (90.0F), recorded both on June 10 and 25.
It comes as autumn begins in an unseasonably warm fashion after a disappointing summer that saw Britain endure its sixth wettest July since records began.
The Met Office said areas in West Yorkshire, Cornwall, Devon and Wales hit heatwave criteria yesterday, with more regions expected to be added to that list today.
While the hottest UK temperature recorded yesterday was 30.7C (87.3F) in West Sussex, forecasters said a new record is likely either today or tomorrow.
Some 13 weather stations have now marked this period as an official heatwave, which is at least three days in a row with daily maximum temperatures meeting or exceeding the heatwave temperature threshold – a figure which varies by region.
Aya Khoury (left), 21, and her friend Ciara Cannel (right), 22, at Bournemouth beach yesterday
Met Office meteorologist Amy Bokota said: ‘As you go through the next couple of days quite a few extra (weather stations) will be added onto that (list).
’32C is expected today, 33C perhaps on Thursday, which is expected to be the peak. It will then be 32C right the way until Sunday for some places in the South.’
Temperatures are also set to reach 27C in Northern Ireland and Scotland, the Met Office said.
The mercury could start to drop gradually at the weekend and there is a chance of thunderstorms breaking out from the North and West of the country, the Met Office added.
Before then, the forecaster is watching a number of September heat records.
If the hottest day of 2023 is achieved this week, it would be the first time since 2016 – and before that the 1950s – that the UK’s warmest day of the year has happened in September.
In addition, the highest temperature of the year has happened in September in just four years over the last century.
There is also a chance of tropical nights this week, which is when overnight temperatures remain above 20C (68F).
The record highest overnight minimum temperature for September is 21.7C (71.1F), which the Met Office said could be challenged tonight and tomorrow night.
This week could also see the highest number of September days and highest number of consecutive September days on record where temperatures reach 30C (86F) or more.
However, the record for the warmest September day on record is unlikely to be broken this week. That record has stood since 1906 when temperatures reached 35.6C (96.1F) in Bawtry, South Yorkshire.
Met Office meteorologist Tom Morgan said: ‘A lot of people will probably think of the summer just gone as being pretty non-exceptional, pretty disappointing if you had plans in the UK.
‘This week, it looks likely that we’ll see the highest temperature of the year so far. Today will be the third day that some sites have seen three consecutive days of heatwave conditions.
‘By the end of today, officially, it will be a heatwave, it is certain that it will be by tomorrow.’
The forecaster said this week will be the first prolonged spell of hot weather the UK has seen since June following an unusually wet July.
Mr Morgan added: ‘We may well be close to some record-breaking temperatures in the next few days. The daytime maximum temperatures are a little less likely to be broken but nonetheless it will be hot so we are watching a couple of records.
‘The most likely record that we could see broken is the highest overnight temperature for Wales. Currently the September highest overnight temperature for Wales stands as 20.5C.
‘The highest UK September temperature we’ve ever seen still stands at 35.6C.
‘So we are very unlikely to see temperatures quite that high but probably a 33C is on the cards either today or maybe also on Thursday, so we are not too far away from the UK record either.’
Met Office chief meteorologist Neil Armstrong said high pressure situated to the South East of the UK was bringing more settled conditions and temperatures well above average for the time of year.
He added: ‘An active tropical cyclone season in the North Atlantic has helped to amplify the pattern across the North Atlantic, pushing the jet stream well to the north of the UK, allowing some very warm air to be drawn north.
‘It’s a marked contrast to the much of meteorological summer, when the UK was on the northern side of the jet stream with cooler air and more unsettled weather.’
The Met Office confirmed it has not issued an extreme heat warning, which covers the UK and aligns with the wider national severe weather warning service.
Two women enjoy the hot weather on Brighton beach in East Sussex yesterday afternoon
Sunseekers enjoy the warm weather on the beach at Bournemouth in Dorset yesterday
A woman sunbathes at St James’s Park in London on a sweltering day in the capital yesterday
A woman plays with a frisbee in the water off Brighton beach in East Sussex yesterday
However, there was a warning issued to pet owners to ensure animals have access to fresh drinking water, good ventilation and shade from direct sunlight.
Dr Justine Shotton, senior vice president or the British Veterinary Association, said: ‘We may be past the peak summer months but it’s important to remember that this September sun and heat is also dangerous for animals.
‘Pets can be extremely susceptible to heat-related illnesses such as heatstroke, and can also suffer sunburn, heart conditions and breathing difficulties, many of which can sadly be fatal. Make sure all pets have access to fresh drinking water, good ventilation and shade from direct sunlight at all times.’
Meanwhile tourism chiefs and MPs criticised the ‘nannying’ warnings from the UK Health Security Agency about the weather yesterday.
The heat health alert, used in situations that can potentially put the whole population at risk, advised people to ‘stay hydrated and keep cool’.
But Conservative MP Peter Bone dismissed the ‘nanny state’ tone, saying: ‘There will be a time when there is a need for a real alert because temperatures are very high. The danger is if you issue them all the time, people ignore them. They ought to be careful about issuing alerts.’
Fellow Tory Giles Watling, MP for Clacton-on-Sea in Essex, added: ‘Obviously for those vulnerable people in society we’ve got to say be careful but I for one welcome the Indian summer. To issue a general warning to the whole population is overplaying it.’
Yasmin, 7, and her brother Nathan, 5, at Birmingham’s Centenary Square Fountain yesterday
People sit in the sunshine outside beach huts on the promenade at Bournemouth yesterday
People enjoy the heatwave on Brighton beach in East Sussex yesterday afternoon
People enjoy the warm weather on Bournemouth beach in Dorset yesterday afternoon
Sir Jacob Rees-Mogg branded the warning ‘ridiculously overblown’, adding: ‘It isn’t for the state to tell you to put on suncream or drink water.’
Malcolm Bell, spokesman and until recently chief executive of Visit Cornwall, pointed out ‘beautiful sea breezes’ would make conditions more bearable along the coast.
He said: ‘The danger is people do the opposite when confronted by the nanny state. Just give them the facts and let them decide.’
And VisitEngland chief Patricia Yates said everyone should take ‘sensible precautions’ but urged them to use the ‘wonderful opportunity to get out and explore the outstanding tourism our country offers’.