Traditional '99' ice cream cones with a chocolate flake are now selling for up to £6 as Britain swelters through what could be its longest heatwave on record.An ice cream van man outside the British Museum in London this week was found to be charging the eye-watering price - but claimed his competitors charged even more.Staff outside the museum confirmed they had seen even higher prices, while vendors at last weekend's British Grand Prix at Silverstone were found to be selling 99s for £5.It comes as more than seven million Brits are now under a hosepipe ban as the nation endures its third heatwave of the year and temperatures soar to 36C today.The scorching conditions which will continue well into next week are leading to early harvests as well as wider impacts on health, energy, wildfire risks and transport.The highest average price for a single scoop cone in Britain is £3.85 at Porthmadog in North Wales, followed by Brighton in East Sussex at £3.71 and New Brighton in Merseyside at £3.70, according to a recent study by credit card company Zable.This is followed by £3.65 in Aberystwyth, £3.57 in Bournemouth, £3.50 in Salcombe, £3.38 in Whitstable and £3.33 in both Tenby and Padstow. The cheapest was Barton-on-Sea in Hampshire at just £1.95, then Tynemouth in North Tyneside at £2.28.Industry organisation the Ice Cream Alliance has cited various pressures contributing to cost rises such as increasing prices for dairy products, flavourings and toppings.Staff wages, energy and fuel prices for mobile operators have also risen significantly in recent years along with the cost of packaging and environmental compliance. People purchase an ice cream from a van in London last month during the extreme heat alert Most expensive average UK seaside ice creamsRank Beach location Region County Price of one scoop cone Price of two scoop cone 1 Porthmadog Wales Gwynedd £3.85 £5.28 2 Brighton South East East Sussex £3.71 £5.96 3 New Brighton North West Merseyside £3.70 £4.70 4 Aberystwyth Wales Ceredigion £3.65 £5.05 5 Bournemouth South West Dorset £3.57 £5.22 6 Salcombe South West Devon £3.50 £5.25 7 Whitstable South East Kent £3.38 £5.00 8 Tenby Wales Pembrokeshire £3.33 £4.83 8 Padstow South West Cornwall £3.33 £4.83 9 Margate South East Kent £3.25 £4.98 Analysis by credit card company Zable The Met Office forecast for London shows temperatures above the 28C heatwave thresholdThe origins of the 99 name are uncertain but Cadbury's launched a shorter version of its Flake bar in 1930 called a 'Flake 99' for the ice cream trade. Others cite how a shopkeeper at 99 Portobello High Street in Edinburgh would break a large Flake in half and put it in an ice cream in the 1920s, giving it its name from the shop number. The 99 typically cost 99p as recently as the 1990s.As the heatwave continues and concerns over a possible drought intensify, Anglian Water today became the latest water firm to announce a hosepipe ban - placing five million customers across eastern England under restrictions from tomorrow.This came hours after Cambridge Water announced a ban for the first time in three decades yesterday for its 350,000 customers which will come into force on July 17.The first ban of summer was introduced by South East Water for 850,000 customers in Kent last Friday; while a Southern Water ban for one million people in Hampshire and the Isle of Wight was activated this morning after being announced last week.Thames Water has urged its 16million customers including those in Greater London to stop using hosepipes during the heatwave but has not imposed an official ban.Officials fear the risk of drought conditions in some parts of the UK is now becoming increasingly likely. Authorities are keeping a close watch on East Anglia, Devon and Cornwall as water companies scramble to manage increasingly tight resources.Meanwhile another record tumbled yesterday when the UK had its eighth day at or above 34C in a calendar year, breaking the previous high of seven days set in the summers of 1976 and 2020. A ninth day of 34C-plus heat is expected today.The Met Office said it was also the first time temperatures of 35C or higher have been recorded in May, June and July of the same year. Rail passengers faced ongoing disruption today due to the heat across the UK network as East Midlands Railway (EMR) continued its 'essential travel only' warning. Paddleboarders Olivia, 20, and Abbie Selby, 17, at Cullercoats Bay in North Tyneside today The parched grass of Greenwich Park in south-east London today as the heatwave continues Two women take a selfie as they visit Greenwich Park in south-east London this afternoon Rowers on the River Thames near Maidenhead in Berkshire during the morning heat today The parched grass of Blackheath Common in south-east London is pictured this morning A beautiful sunrise over Glastonbury Tor in Somerset today as the heatwave continuesCustomers were urged to travel before 12pm to avoid the highest temperatures, with regional services between Nottingham and Worksop and Nottingham and Leicester being suspended from that time to reduce the impact of the heat on the railway.Great Western Railway, c2c, London Northwestern Railway, South Western Railway, Northern Transport for Wales and West Midlands Railway were also running amended services due to the weather.High temperatures can cause rails to buckle, overhead electric wires to sag and lineside fires, while steel rails can exceed 50C when the air temperature is 30C. Hosepipe bans and requests from firms Anglian Water: Hosepipe ban for five million customers across eastern England begins at 1am tomorrowSouthern Water: Hosepipe ban for one million people across Hampshire and the Isle of Wight, in force from todaySouth East Water: Hosepipe ban for 850,000 people in Kent, in force since last week. People in Hampshire and Sussex asked to reduce water useCambridge Water: Hosepipe ban for its 350,000 customers from July 17Thames Water: 16million customers asked to stop using hosepipes during heatwaves but no ban is in place Separately, industrial action by the TSSA union was impacting London Northwestern and West Midlands services both today and tomorrow.Anglian Water said its customers will not be allowed to use hosepipes for watering gardens, washing cars or filling swimming and paddling pools from 1am tomorrow, but asked that people 'live within the spirit of these restrictions immediately'.Dr Geoff Darch, head of strategic asset planning for Anglian Water, said: 'This year has been exceptionally hot and dry, and we're already into the third heatwave of the summer.'Every day of sustained hot weather increases the challenge of balancing supply and demand, and we are now at the point where we need to ask customers to help by hanging up the hosepipe, letting lawns go brown, cars go dirty and using water even more wisely to help protect the environment and ensure water remains available for all customers.'Temperatures have now been above 30C in south-east England for five days in a row.Wisley in Surrey has been the UK's hottest place for the past two days, with highs of 35.5C yesterday and 33.8C on Wednesday.Prior to that, London was the hottest area for four days in a row – with 32.4C in Teddington on Tuesday, 34.0C in Teddington on Monday, 30.3C at Heathrow on Sunday, and 29.3C in Teddington on Saturday.