Half of England was officially in drought on Monday after the Environment Agency declared another 17 counties short of water, and warned the situation may continue until the end of the year.
Despite rain across the country last week, two dry winters have left rivers and ground waters depleted, prompting the government agency to urge businesses, water companies and consumers to be more careful in their use of water.
A ban on garden hoses has already been introduced in southern and eastern England, affecting about 20 million people.
Officials had hoped for more rain over the past six months, a period known as the "winter recharge period", but parts of England received less than 60 percent of the average winter rainfall during that time.
"A longer term drought, lasting until Christmas and perhaps beyond, now looks more likely," said Trevor Bishop, head of water resources at the Environment Agency.
The agency had already declared drought zones in London, the south east, East Anglia and parts of Yorkshire in northern England, and on Monday it extended this to the southwest and the Midlands.
While public water supplies in these areas are unlikely to be affected, the agency said there would be problems for wildlife and wetlands, as well as for farmers' crops.
Explore further: Britain faces drought after dry winter