Five million people in Yorkshire, Lincolnshire and Derbyshire affected.
Million of drivers across Britain have been told to stop washing their cars under the first warning of its type seen in 2025.
On Tuesday, Yorkshire Water announced a temporary use ban (TUB) on hosepipes that comes into effect from 11 July, restricting their use for watering gardens, filling pools, jet-washing patios, and - importantly for motorists - washing their cars.
It's the first hosepipe ban to be declared this year after the particularly high temperatures seen in recent weeks.
Yorkshire Water's ban comes after the heatwave saw the warmest and driest spring period on record.
It said that the region has had only 15cm of rainfall between February and June - less than half what is expected in an average year.
Yorkshire Water's hosepipe ban affects more than five million people and applies to customers across Yorkshire, parts of Lincolnshire and Derbyshire.
There are around 2.6 million licensed cars in the Yorkshire and Humber region that may have to go dirty as a result of the ban. Flouting the rules could see people fined up to £3,000.
Yorkshire Water has announced a hosepipe ban coming into effect 11 July that will affect five million people, meaning drivers won't be allowed to use a hosepipe to wash their cars.
Dave Kaye, director of water at Yorkshire Water, told the BBC that the restrictions 'are intended to make sure we have enough supply for the essential needs of people across the region this year and next as well as making sure we are able to protect our local environment'.
It comes after the Environment Agency declared a drought across the region last month.
Reservoir levels currently stand at just over 50 per cent - 'significantly below' the 80 per cent average for early July.
Reservoir stocks have been falling since the last week of January and there's been no standard spring rainfall to top supplies up.
Reservoir levels in Yorkshire are just 50%, down from the 80% average at this time of year. Yorkshire Water has promised to lift the ban as soon as possible but the UK is looking at yet another heatwave from next week.
Mr Kaye said: 'Having restrictions in place also allows us to apply for drought permits from the Environment Agency, which means we can abstract more water from our rivers and reduce compensation flows out of our reservoirs so that we can continue to provide the water our customers rely on us for.'
He added: 'The ban will be in place until the region has seen significant rainfall to bring reservoirs and groundwater stocks back to where they need to be. This may last into the winter months, but we will lift the usage restrictions as soon as we are able.'
This comes before a third heatwave is predicted to hit the UK by the end of next week, with temperatures expected in the low 30s.
If there's a hosepipe ban in place drivers can still wash their car by using tap water from a bucket or watering can.
This is what we'd recommend drivers in Yorkshire doing while the ban is in place.
Alternatively, you can still go to a car wash as these will still be operating during a hosepipe ban.
TUBs restrict personal but business use is still allowed, meaning commercial car washes are typically exempt and can continue to use their water supply.
Car washes often have their own water supply or have recycled water systems in place too.
This is Money has reached out to Yorkshire Water for comment.