More than 40million people have been hit with a hosepipe ban or told to watch their water usage as Britain swelters under its third heatwave this year.

Five water companies now have severe restrictions in place – preventing about 11million from using hosepipes to water plants and lawns, wash cars or fill paddling pools.

A further 33million are being urged to be ‘mindful’ of their water usage. This advice often precedes a hosepipe ban.

Experts warn that the risk of a drought is increasing as temperatures of more than 35C (95F) were recorded in places such as Derbyshire and Hertfordshire yesterday.

Anglian Water’s restrictions, which will affect five million residents across the East of England, will come into force today.

Dr Geoff Darch, the company’s head of planning, said: ‘We are now at the point where we need customers to help by hanging up the hosepipe, letting lawns go brown and cars go dirty.’

Affinity Water also told 3.8million customers across areas including Bedfordshire, Berkshire and Surrey to control their usage ‘immediately’, with a full ban coming into force next Friday.

Southern Water has also introduced a hosepipe ban, affecting about one million customers across Hampshire and the Isle of Wight.

The parched grass of Greenwich Park in south-east London on Friday as the heatwave continued

And Cambridge Water has brought in restrictions for its 350,000 customers – warning that resources are ‘now under significant pressure’. 

Last week, South East Water introduced a hosepipe ban for about 850,000 customers across Kent, including Ashford, Canterbury, Faversham, Maidstone, Sevenoaks and Tunbridge Wells.

Once a relatively rare measure – there was only one major hosepipe ban between 2012 and 2021 – the measure has become a regular summer feature in recent years as temperatures rise.

Yesterday, temperatures peaked at 35.2C at Coton in the Elms, Derbyshire. It marked the first time temperatures of 35C or higher had been recorded on six separate days in a year, the Met Office said.

Water companies are now also being urged to improve their infrastructure to cope with more frequent high temperatures.

Mike Keil, chief executive of the Consumer Council for Water, said: ‘There is no hiding away from climate change and what was once considered to be extreme is rapidly becoming the new normal.

‘Water companies have been entrusted with an unprecedented amount of customers’ money through large water bill rises to confront this challenge and they now need to get on and deliver the nine new reservoirs and other network improvements they have promised.

‘Some of these changes will take time but water companies should look to beat – and not just meet – their leakage reduction targets and use the largest ever rollout of smart water meters to help people not only save water but understand why it matters.’

A woman sunbathed at the beach under an umbrella in Exmouth, Devon, on Friday afternoon

Paddleboarders Olivia, 20, and Abbie Selby, 17, at Cullercoats Bay in North Tyneside on Friday

In other areas, Thames Water said the heatwave had resulted in a 30 per cent rise in water usage, with one billion extra litres being consumed in London alone.

The firm has asked its 16million customers to limit their usage but stopped short of a hosepipe ban.

Essex and Suffolk Water also warned 300,000 customers to be ‘mindful’ of their water usage.

Kieran Ingram, the company’s water director, said: ‘By making wise choices now, our customers can help lower the risk of [a hosepipe ban] being needed.’

Portsmouth Water, Wessex Water, Severn Trent Water and Yorkshire Water issued similar pleas to almost 17million customers.

It comes after officials warned that drought conditions in some parts of the UK, including East Anglia, Devon and Cornwall, are becoming increasingly likely.

Temperatures have now been above 30C in south-east England for five days in a row.

Wisley in Surrey was the UK’s hottest place on Wednesday and Thursday, with highs of 35.5C and 33.8C.

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.

Parts of south-east England have now officially been in a heatwave since last Saturday and forecasters believe the threshold will continue to be met well into next week.

The conditions could yet be record-breaking, given the historic 1976 heatwave lasted for 16 days in a row with at least 30C in London each day from June 23 to July 8.

The current heatwave was expected to peak on Friday with highs of 36C in the South-East before easing slightly to 30C this weekend and 28C early next week.

But these temperatures will still be enough to hit the heatwave level, which varies around the UK but is 28C in London and must be recorded for at least three days.

Forecasters said conditions will turn slightly cooler but remain dry from next week in the South-East due to an easterly wind, while the focus for the hottest conditions will shift towards south-west England where there could also be thunderstorms.