The longest heatwave for seven years is set to continue across Britain - but the blazing temperatures will bring widespread rain and thunderstorms next week.

Forecasters expect a slightly cooler weekend than in recent days, followed by a surge to 32C (89.6F) or possibly 33C (91.4F) in local areas on Monday and Tuesday.

The hot weather has taken its toll on the UK, with grass fires in London, mountain blazes in the Welsh valleys and forest fires in Fife, Scotland.

The heatwave is believed to have caused up to 760 premature deaths already, and the British Red Cross has launched two call centres in Norwich and Ipswich to check on the welfare of hundreds of elderly and vulnerable people in the region.

Britain will have a little respite from the extreme temperatures over the weekend, feeling fresher in eastern areas with more cloud and breezes coming in from the North Sea, weather experts said.

James Wilby, a forecaster with MeteoGroup, the weather division of the Press Association, said western Scotland, western Northern Ireland and the southern counties of England will be the hottest areas, with temperatures reaching 27C (80.6F) or 28C (82.4F), while eastern counties will see 22C (71.6F) or 23C (73.4F).

"Sunday will be warmer, with 29C in the southern counties, but Monday will be the warmest day, with 32C (89.6F) possible just south of London, and perhaps 33C (91.4F) in localised areas," Mr Wilby said.

"Tuesday will see similar conditions to Monday, but on Wednesday and Thursday it will be between 26C (78.8F) and 28C (82.4F)."

Showers and thunderstorms will hit the South West tomorrow, spreading through western parts of the UK on Monday. By Tuesday heavy, thundery rain will be more widespread, and thundery showers are expected to cover most of the country by Wednesday, Mr Wilby said.

Despite the prolonged heatwave, temperatures are unlikely to top the high of 36.5C (97.7F) recorded in Surrey in July 2006.

The Met Office has warned of an "elevated risk" of fires in the countryside following six consecutive days of plus-30C temperatures and a dramatic reduction in the average monthly rainfall.

Level three heatwave health warnings have been issued for western parts of the country. The South East, East Midlands, Yorkshire and the Humber are at level two. The North East and East remain at level one.

Police and fire chiefs have reiterated warnings about escaping the heat by swimming in open water after a number of deaths in recent weeks. Four people died in separate incidents on Tuesday in lakes, rivers and the sea in Norfolk, the Shropshire-north Wales border and Cornwall.

Officers in Lincolnshire reported another death yesterday afternoon, after a woman was pulled from the sea in Skegness.

Emergency services were called to the beach area behind the Beachcomber on Roman Bank, Ingoldmells, shortly after midday.

Officers said the 69-year-old woman's death was not being treated as suspicious.

Elsewhere, a four-week-old baby was among 10 children admitted to one hospital with sunburn since the period of hot weather began.

Six of the 10 patients - of which the oldest was 14 - needed specialist treatment after being referred to the Queen Victoria Hospital in East Grinstead, West Sussex, from other hospitals because of the severity of their burns.

The balmy temperatures have also proved difficult for some motorists, with roadside recovery firms reporting a spike in weather-related breakdowns.

Elsewhere wildfires have also seen emergency services stretched.

Crops due for imminent harvest are said to be particularly vulnerable to blazes.

In London, firefighters have tackled dozens of grass fires since Wednesday afternoon, including at Mitcham Common on Thursday when flames burned through grass and gorse in an area the size of four football pitches.

Insurers have warned wildfires could put lives at risk and cost millions of pounds in damaged crops and machinery.

Farmers have been urged to ensure that their fire extinguishers are well maintained and to reduce the risk of combine harvesters catching fire by regularly cleaning the machinery to remove chaff and dust.

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  • Summer weather July 19th

    People relaxing by the fountains at Marble Arch in London.

  • Summer weather July 19th

    Children playing in fountains as they enjoy the continuing hot weather in the City Square, Bradford.

  • Summer weather July 19th

    Children playing in fountains as they enjoy the continuing hot weather in the City Square, Bradford.

  • Wanstead fire

    Firefighters tackle a grass fire on the edge of Epping Forest near Wanstead in north east London.

  • Summer weather July 19th

    Children playing in fountains as they enjoy the continuing hot weather in the City Square, Bradford.

  • Summer weather July 19th

    Swimmers and sunbathers enjoying the hot weather in the mixed bathing ponds of Hampstead Heath, in north London.

  • Wanstead fire

    Firefighters tackle a grass fire on the edge of Epping Forest near Wanstead in north east London.

  • Summer weather July 19th

    Swimmers and sunbathers enjoying the hot weather in the mixed bathing ponds of Hampstead Heath, in north London.

  • Summer weather July 20

    The cappuccino cycle club climb a hill in Harrogate, North Yorkshire as the longest heatwave for seven years is set to continue across Britain - but the blazing temperatures will bring widespread rain and thunderstorms next week.

  • Summer weather July 9

    Sisters Lauren, 23 and Ashley, 25 Johnstone (right) from Gateshead enjoy the heatwave at Whitley Bay, North Tyneside, during the hot weather that the UK has been enjoying which is expected to last into the weekend.

  • Summer weather July 9

    Sisters Lauren, 23 and Ashley, 25 Johnstone (right) from Gateshead enjoy the heatwave at Whitley Bay, North Tyneside, during the hot weather that the UK has been enjoying which is expected to last into the weekend.

  • Summer weather June 20

    A child playing in the water fountain at the South Bank Centre in London

  • Heatwave in the UK

    Mud flats at Wallasea Island, Essex, after baking in scorching temperatures over the past few days.

  • Weather June 26th

    People soak up the sun on the deckchairs in central London's St James's Park.

  • Heatwave Hits Bedfordshire

    Chimpanzees Bonnie and Elvis enjoy a block of fruit filled ice as temperatures soared at Whipsnade Wild Animal Park in Bedfordshire.

  • Summer Weather July 12

    People walk along the dried up bed of the river Hodge Beck in Kirkbymoorside in North Yorkshire as the heatwave continues up and down the country.

  • Summer Weather July 12

    People walk along the dried up bed of the river Hodge Beck in Kirkbymoorside in North Yorkshire as the heatwave continues up and down the country.

  • Summer Weather July 12

    People walk along the dried up bed of the river Hodge Beck in Kirkbymoorside in North Yorkshire as the heatwave continues up and down the country.

  • Summer Weather July 12

    People walk along the dried up bed of the river Hodge Beck in Kirkbymoorside in North Yorkshire as the heatwave continues up and down the country.

  • Summer Weather July 12

    People walk along the dried up bed of the river Hodge Beck in Kirkbymoorside in North Yorkshire as the heatwave continues up and down the country.

  • Summer weather July 16th

    Summer Passmore, two, from Clerkenwell, London, cools off in the pavement fountains at the Royal Academy court yard in central London, as the hot weather continues to cover the UK.

  • Summer weather July 16th

    Summer Passmore, two, from Clerkenwell, London, cools off in the pavement fountains at the Royal Academy court yard in central London, as the hot weather continues to cover the UK.

  • Summer weather July 16th

    Luella Facer (left) and her friend Summer Passmore, both two and from Clerkenwell, London, cool off in the pavement fountains at the Royal Academy court yard in central London, as the hot weather continues to cover the UK.

  • Summer weather July 16

    American tourists Lyndsey, 20, (left) from Oklahoma and Brooke, 23 from Texas, relax by a fountain in Trafalgar Square, London as the hot weather is set to continue for the rest of the week.

  • Summer weather July 16th

    Summer Passmore, two, from Clerkenwell, London, cools off in the pavement fountains at the Royal Academy court yard in central London, as the hot weather continues to cover the UK.

  • Summer weather July 15th

    A visitor to Green Park, London, enjoys the Summer weather.

  • Summer weather July 15th

    Punt Chauffeurs Hannah Taylor, 20, and Flo Esplin (right), 18, enjoy the summer sunshine as they take a break between trips on the river Cam in Cambridge.

  • Summer weather July 15th

    Visitors to Green Park, London, enjoy the Summer weather.

  • Summer weather July 16

    People relax in deck chairs in St.James Park, central London as the hot weather is set to continue for the rest of the week.

  • Summer weather July 16th

    A man relaxes in the hot weather in Victoria Tower Gardens in London.

  • Summer weather July 16th

    A man relaxes in the hot weather in Victoria Tower Gardens in London.

  • Summer weather July 16

    Black cab driver Tom Rudland, from Surrey, cools down with an ice cream in central London as the hot weather is set to continue for the rest of the week.

  • Summer weather July 15th

    A man and woman stand on a narrow boat in the River Thames near Penton Hook, Surrey, as the hot weather continues across the UK.

  • Summer weather July 16

    People cool down in the fountain at Trafalgar Square, London as the hot weather is set to continue for the rest of the week.

  • Summer weather July 16th

    People relaxing in the hot weather in Victoria Tower Gardens in London.

  • Summer weather July 16th

    People relaxing in the hot weather in Victoria Tower Gardens in London.

  • Summer weather July 15th

    A young woman walks through a field of linseed in Fenny Drayton, Leicestershire.

  • Summer weather July 15th

    A young woman walks through a field of linseed in Fenny Drayton, Leicestershire.

  • Summer weather July 15th

    A young woman walks through a field of linseed in Fenny Drayton, Leicestershire.

  • Summer weather July 15th

    A young woman sits in a field of linseed in Fenny Drayton, Leicestershire.

  • Summer weather July 15th

    Punt Chauffeurs Flo Esplin (left), 18, and Hannah Taylor, 20, enjoy the summer sunshine as they take a break between trips on the river Cam in Cambridge.

  • Summer weather July 15th

    Punt Chauffeurs Flo Esplin (left), 18, and Hannah Taylor, 20, enjoy the summer sunshine as they take a break between trips on the river Cam in Cambridge.

  • Summer weather July 15th

    A visitor to Green Park, London, enjoys the Summer weather.

  • Summer weather July 15th

    A woman relaxing on a park bench in the hot weather in Regent's Park, central London.

  • Summer weather July 15th

    A man sunbathing in the hot weather in Little Venice, west London.

  • Summer weather July 15th

    Punt Chauffeurs Hannah Taylor, 20, and Flo Esplin (right), 18, enjoy the summer sunshine as they take a break between trips on the river Cam in Cambridge.

  • Summer weather July 15th

    Punt Chauffeur Flo Esplin, 18, enjoys the summer sunshine as she takes a break between trips on the river Cam in Cambridge.

  • Summer Weather July 6

    Alex (left) and Andrea Pal with their son, Leonardo, aged six-months, from Dagenham, Essex, enjoy the sunshine on the beach at Southend-on-Sea as much of Britain is bathed in sunshine.

  • Summer Weather July 14

    People enjoy the warm weather along the River Avon in Stratford-upon-Avon.