Get ready for the heat wave! Mercury is expected to rise to 32°C (90°F) and Brits brace themselves for what may be the hottest September night on record as parts of the UK are expected to meet official heatwave criteria TOMORROW

On the final day before children return to school, families are enjoying the heatwave on Britain’s beaches as temperatures are expected to hit 29C today.

After a rather gloomy summer, the start of autumn will bring brighter days, with mid-week mercury temperatures expected to reach highs of 32°C.

Photos show Britons soaking up the sun at popular seaside resorts, lakes and parks across the country on Monday.

According to the Met Office, a jet stream – which has brought largely fickle weather to the UK – continues to shift north, which could allow higher pressures to build up across the UK.

It also explains a second reason for the heatwave: Former Tropical Cyclone Franklin was moving further into the North Atlantic, amplifying high-pressure buildup.

Chris Bulmer, the Met Office’s deputy chief meteorologist, said: “Good and consistent conditions will develop and with that we will see a rise in temperatures across most of the UK next week.”

Families play on New Brighton beach as temperatures are set to rise today

Revelers are flocking to the beaches with their kids as the mini-heatwave is in full swing

After a somewhat dull summer, the beginning of autumn makes up for it – in the picture today

The public relaxes on Tower Hill in central London today in hot and sunny weather

A weather map for today – temperatures are getting hotter – and will continue to rise this week

He added: “Many locations can expect maximum temperatures to rise to 25C or more for several days, which would put some locations in the realm of heatwave conditions.”

“Although the highest temperatures are likely to be in the south and east of England, those areas also have higher temperature thresholds for reporting heatwaves.”

“While some areas may fall just short of true definition, regardless of thresholds, many areas will enjoy a fine weather spell with plenty of sunshine and temperatures are likely to be their highest since June or early July for many.”

“By mid-week there will be blanket sunshine in most places, which we haven’t seen for most of the summer,” said Amy Bokota, Met Office chief meteorologist.

“It will feel warmer in early autumn than we would expect, particularly in London and the South East where the heatwave threshold could be approached.”

“But it will also feel damp and muggy in some areas, with temperatures staying above 20°C (68°F) overnight in parts of the country, making sleeping conditions uncomfortable.”

A paddle boarder enjoys the autumn sunshine at Derwent Water, Keswick, Cumbria

A dog cools off in the autumn sunshine at Derwent Water, Keswick, on Monday

A woman walks her dogs along the beach in New Brighton today

Warm, sunny weather prevailed across the country over the weekend, with beachgoers flocking to seaside resorts from Bournemouth in southern England to resorts in the north.

Seaburn Beach in Sunderland was packed with families ending the school holidays in style.

Surfers and swimmers went to the North Sea when the temperatures were mild, others brought buckets and spades with them.