Water providers are experiencing supply issues due to the hot weather, with some reporting lower pressure levels and others warning of further disruption.
Affinity Water said the heat is resulting in lower water pressure in areas such as London, Essex and Surrey.
The company urged customers to avoid non-essential water usage and said it predicts an extra 164 million litres of water will be needed on Monday compared to normal demand.
“Because of the hot weather, many of us are using much more water,” the provider said.
“This means you may notice lower pressure or no water when demand is higher in your area.”
Anglian Water, which operates in the east of England, said sudden high demand due to “extreme hot weather” is likely a contributing factor in causing interruptions to water supply in King’s Lynn over the weekend.
A spokesman said its teams are working to restore water supplies “as quickly as possible” in some areas of King’s Lynn following a burst water main.
Similar weather-related supply issues are being seen in Bristol, with Bristol Water Foundation warning this week’s heatwave might affect the pressure and taste of its water.
“With the weather getting warmer, you may experience a drop in water pressure, especially during peak times,” it told customers.
“As temperatures rise, water use tends to increase as we all try to cool down with showers, hoses and paddling pools, which increases the demand on our network.”
It said water supplies might be temporarily redirected so customers’ water comes from different treatment works or reservoirs than usual.
“This may mean you notice your water tastes a little bit different to normal. Don’t worry, though, this will return to normal as temperatures start to cool down again,” it said.
Meanwhile, South East Water reported supply issues in the Challock and Molash area of Kent on Sunday, caused by an unprecedented amount of water usage.
The company has set up a bottled water station and told customers the continuous hot weather and increased demand for water “has put a significant pressure on our network”.
South East Water told the PA news agency: “Despite seeing record demands for water, we are currently seeing minimal customers’ supplies interrupted due to hot weather in our water supply region of parts of Kent, Sussex, Surrey, Hampshire and Berkshire.
“We would like to thank our customers who have been listening to our water efficiency messaging and ask them to increase their efforts to reduce their water use while we move into the hottest period so far.
“In the villages of Challock and Molash, we have rezoned our water network so some customers will still have a supply of water but there may be a few without so we have set up a bottled water station at Challock Village Hall, which will be open until 9pm.”