This was the moment a woman frantically struggled to stay afloat after tumbling from a punt in Cambridge. And the terror etched on her face is very real, because she cannot swim. The woman, who was with three friends, is believed to have lost her footing and fallen from the deck after her punt hit another boat. She disappeared under the waters of the Cam several times, screaming for help each time she resurfaced. Two of her friends leapt in to save her and staff at a punt hire operator manoeuvred one of their craft alongside to help pull her out. Scroll down for video . As the sun made its long-awaited appearance, a woman believed to be in her 20s, had to be rescued from the River Cam, Cambridge, after almost drowning while punting (pictured left and right) Safety: The woman, who couldn't swim, was pulled to safety by her friends after she disappeared under the water for several seconds . The tourist, who was standing up on the punt ferrying three friends, is believed to have fallen into the freezing water after her vessel hit another boat in the university city . She was bundled into her rescuers’ punt by her friends and could be seen holding her head in her hands. An onlooker to Saturday’s drama said: ‘I heard a splash and a cheer went up, which is what normally happens when someone falls in. A woman was flapping about and two people in the punt jumped in and grabbed her. ‘It took them about 15 to 30 seconds to get to her and the whole thing only lasted a minute but she did go under a few times. It wasn’t nice to watch. For someone who can’t swim to be standing on a slippery punt is just bonkers. ‘The Cam is at least six to seven feet deep in places. Everyone involved was in shock and shaking afterwards.’ Meanwhile, Britons were  given their first taste of spring with temperatures reaching nearly 21C - marking the hottest day of the year so far. With forecasters predicting temperatures higher than in Rome and Athens, families flocked to parks, beaches and promenades across the UK to make the most of the balmy Easter weather. Teresa Kingston inspects the bloomed daffodils amid the blue skies and warm sunshine around Alnwick Castle in Northumberland today . The daffodils shone in the sunshine as temperatures soared to their high teens, thanks to a high band of pressure across the UK . Spring's here: Tilly, two, makes the most of the unseasonably warm Easter weather as she enjoys a paddle at Whitsand Bay, Cornwall . The girl, pictured with her mother Tessa, was among hundreds of Britons who flocked to beaches and parks today to enjoy the sunshine . Crowds flocked to Bamburgh beach in Northumberland today, making the most of the soaring temperatures and bright sunshine . Northumberland was one of the warmest areas today, although the high temperatures are likely to move south as the week goes on . The glimpse of sunshine brought families, swimmers, surfers and dog-walkers out in droves along the stretch of sand . Yesterday, highs of 20.5C were recorded in Aboyne, Aberdeenshire - some 4C higher than the previously recorded hottest day of the year. And according to experts, today's unseasonably warm weather is just the beginning of a week-long spell of sunshine, which could stick around until the end of the week. By Friday, temperatures could again reach highs of 21C in the south of England, prompting a glorious weekend of sunshine. That will come after a largely dry and bright week, which will see above average temperatures across most of the British Isles. Met Office Forecaster Craig Snell said: 'By Friday, it could be 19C or 20C down towards the south of England. Although it will be more unsettled across parts of Scotland, it will be a fine week for the second part of the Easter holidays.' Today, parts of Scotland and Northumberland basked in temperatures of 18C, while the mercury also hovered around 17C in parts of Devon and Cornwall, Somerset and the Midlands. But sea fog lingered over the north west keeping Blackpool and Cumbria murky. Parts of the south coast, including Brighton, Norfolk and East Anglia, also stayed cloudy, but saw some sunny spells. Mr Snell said this morning: 'North east England and the east coast of Scotland could experience the warmest day of the year so far where temperatures are expected to be between 17C and 18C. This three-day forecast shows sunny spells today across Scotland and south west of England, while the next few days will be warm, despite lingering cloud in some parts . A surfer stands and watches the sunrise before heading out for a morning Easter surf today at Saltburn . The sunrise, which cast ribbons of pale pink and purple across the sky, marked the start of a warm, sunny day across most of the UK . Children rode their bikes through the water fountains in Millenium Square in Bradford after the early grey clouds gave way to sunshine . The weather is the start of a week-long spell of sunshine, which will create a fine week for schoolchildren in their second week of holidays . As the sun shines, children are seen playing in the water fountains in Millennium Square in Bradford on Easter Sunday . The mercury had been expected to reach higher than in Mediterranean hotspots such as Rome and Athens. Pictured: A cyclist enjoying the warm weather in Bute Park, Cardiff . Today's warm temperatures are the beginning of a week-long spell of sunshine, which forecasters say will remain until the end of the week. Pictured: A girl relaxes in Bute Park, Cardiff, today . The mercury was also expected to hover around 17C in parts of Devon and Cornwall, Somerset, south Wales (pictured) and the Midlands . 'If temperatures reach 17.6C it will beat the 17.5 (63.5) recorded in Northern Ireland on March 7, which was the warmest day of the year so far. 'Newcastle, the Northumbrian coast, Edinburgh and Aberdeen are expected to be particularly warm. There is a band of high pressure over all of the UK with quiet weather expected over the country. 'The best of the sunshine will be across parts of Wales and south west England and north east England and the best of the sunshine will be there too. The south west coast of Wales is also expected to be nice.' He added:  'Those wanting to experience the best of the Easter weekend should head to Devon and Cornwall and Northumberland nd should avoid Blackpool and the Norfolk coast.' The picturesque Backs in Cambridge were particularly busy this afternoon, as punters made the most of the brighter Bank Holiday weather after a week of storms and rain. A scooter is ridden along the sea front this morning in Scarborough, as part of the Scarborough Scooter Rally . Others relaxed on the nearby beach, enjoying the balmy temperatures. It reached 21.5 in parts of Scotland today . Hundreds of sun-seekers were also spotted in Bournemouth, where temperatures dipped to around 14C due to the sea breeze. Sarah Anderson, 38, from Bournemouth, said: 'It definitely feels like winter is behind us and the temperatures are going to get hotter from now on. 'So often Bank Holidays in this country are a bit of a washout so when the sun comes out you have to make the most of it.' Meanwhile, a distressed pregnant woman was rescued from the sea after her yacht capsized. The woman was sailing with her partner when they were thrown from the boat and had to cling to the wreckage of the sinking trimaran near Dungeness, Kent. Dover Coastguard crews reached the couple after spotting a lit red flare and the pair were flown to William Harvey Hospital. Bob Giles, Dover Coastguard watch manager, said: 'The couple were thrown into the water after their vessel capsized. 'Both were wearing lifejackets and the man, ensured that his partner was safe, then tied a rope around himself and dived under the vessel to retrieve a flare so that he could alert rescuers to their position. 'Because they had AIS (automatic identification system) on board they were easy to locate and so were rescued quickly. The warmest Easter on record was in on April 23, 2011, when the mercury hit 27.8C. The coldest was on March 31, 2013, when it plunged to -12.5C. Martina Cibis, who lives in Salisbury, takes a photograph of a tree in spring-time blossom in Imperial Square and Gardens in Cheltenham . Martina Cibis (left) and her mother Hanna Cibis (right) take photographs of a tree in blossom in Imperial Square and Gardens in Cheltenham . Karina and Slawek, from Cheltenham, enjoy ice creams in the sunshine while sat on a bench in the gardens .
Temperatures reached  20.5C in Scotland today, while highs of 17C were seen across the south west and Wales .
Best of sunshine was in Scotland and Northumberland, while Norfolk, Suffolk, Essex and Kent remained cloudy .
Today's warm weather is the start of week-long spell of sunshine, which could culminate with 21C high on Friday .
Tourist, in her 20s, had to be rescued in Cambridge after toppling into the water while punting with three friends .