Temperatures will rocket through the coming days with parts of the country braced for a 30C (86F) steam-bath next weekend.
Blazing sunshine and blue skies should hold out until the middle of June although some forecasters predict a month-long scorcher.
Fine weather will make a welcome return after violent electrical storms pummelled the nation unleashing lashing rain, hail, floods and tens of thousands of lightning strikes.
Unseasonal warmth and sweltering humidity will bring an ongoing risk of thundery outbreaks during the start of summer although they will be fewer and less severe, experts say.
James Madden, forecaster for Exacta Weather, said the mercury will take an upward turn this weekend before rocketing through the following week.
He said: “Forecasts into the start of the meteorological summer reveal a settled pattern of warm to hot temperatures with no give until at least mid-June.
“We expect it to turn increasingly warmer through the first week of the month with many parts of the country basking in temperatures in the mid 20Cs.
“It could be rather muggy and humid with some variable cloud cover, but when the sun does come out it will feel extremely hot as summer gets underway.”
Storms which have blighted Britain over the past few days will deliver their parting shot across Scotland and eastern England on Saturday.
The Met Office has issued warnings for torrential and disruptive rain across the region from mid-morning until 9pm.
Unsettled weather threatens further traffic delays and problems with power supplies with flooding likely to cause damage to homes and businesses.
The Environment Agency has almost 50 flood alerts in place across central and northern England as river levels continue to rise after a week of downpours.
A spokesman said: “Surface water flooding is possible across parts of eastern and northern England on Saturday.
“Flooding may also occur from rivers in these areas, especially smaller rivers through towns and cities.
“Land, roads and some properties may flood and travel disruption is likely.”
Met Offie chief forecaster Andy Page warned heavy, thundery showers will dump almost three inches of rain across northern Britain on Saturday.
He said: “Heavy showers and thunderstorms are expected to develop by late morning mainly across inland parts of Scotland and Northern Ireland.
“Some of the storms could be severe, and with generally light winds, will be slow-moving.
“Whilst some areas may escape with a dry day, where storms do develop, torrential downpours are possible.
“There is the potential for 20 to 30 mm of rain to fall in an hour and as much as 40 to 70 mm [2.7 ins] in two to three hours.
“As well as heavy rain, frequent lightning and large hail are also possible.”
Despite the unsettled start to the weekend much of the country will enjoy a return to the freakishly hot weather which has been the theme since early spring.
Temperatures will rise across the nation through next week before the next round of blowtorch heat arrives after the weekend.
Heatwave conditions over Europe will push into Britain nudging temperatures towards the 30C (86F)-mark in parts, according to WeatherAction.com forecaster Piers Corbyn.
He said: “The first week of June looks like dishing up a bit of a mixed bag, although it will start to turn warmer and more settled there will be some more thunderstorms around.
“However it is from the second week of the month onwards when we expect to see a return to heatwave conditions, very hot weather is expected over Europe and some of that is going to influence the UK.
“We expect this to continue through to mid-month after which it will continue to be vary warm with another heatwave situation expected at some point.
“Temperatures could hit 30C (86F) next weekend, so apart from a slightly cooler start and end to the month we expect a blazing June of sunshine and dry weather.”
Temperatures will hover in the low to mid-20s across much of the UK through the weekend and into next week, the Met Office said.
Much of the country will enjoy fresher drier conditions with plenty of sunshine away from the east coast which will be cloudier.
Met Office spokeswoman Nicola Maxey said: “There will be some quite heavy, thundery downpours in Scotland, northern Ireland and along the east coast on Saturday although elsewhere it is looking fresher and sunnier.
“Sunday will bring more sunshine with highs of 25C (77F) possible in parts and again it will feel less humid and much more comfortable, especially at night.
“Next week will bring more sunny spells and similar temperatures.”
The Met Office’s long-range outlook points towards generally dry, warm weather continuing into the middle of June.
It states: “It will be warmest in the west, but cooler along North Sea coasts, with some mist and fog lingering here. These conditions are likely to last through the weekend, but as we move towards the middle of the month the forecast becomes much more uncertain.
“There is always a risk of scattered heavy showers and thunderstorms could affect southern and western parts at times, but there will be some dry and bright weather here too.”
Hot weather last month is likely to have brought a record-breaking set of May temperature and sunshine records, according to government forecasters.
The provisional average daily maximum temperature for May was 17C (62.6F) making it the warmest since 1910 beating the 16.9C (62.42F) set in 1992, the Met Office said.
More than 245 hours of sunshine also brought the sunniest May in records dating back to 1929 beating 1989 when 241.7 hours of sunshine baked Britain during the first month of spring.
Tim Legg, spokesman for the Met Office’s National Climate Information Centre, said: “Increased sunshine during the month has helped to keep daytime temperatures high, leading to it provisionally being the warmest May since records began in 1910.
“It is also likely to be the sunniest May since 1929.”