The UK's meteorological authority said this year saw record low rainfall in England and Wales coupled with extreme heat.
The UK government has officially declared a drought across swathes of England, following months of record low rainfall and unprecedented high temperatures in recent weeks.
At Friday's meeting of the National Drought Group, the government's Environment Agency said the "drought trigger threshold had been met" in parts of southwestern, southern, central and eastern England.
A drought was last officially declared in England in 2018. The agency has released a report noting that England had its driest July since 1935.
The Met Office, the UK's meteorological authority, said the period from January to June this year saw the least rainfall in England and Wales since 1976.
That summer saw the use of drastic measures such as roadside standpipes and water rationing.
This year's exceptional weather comes as France is also experiencing a record drought and battling huge wildfires.
The Environment Agency and water companies "will step up their actions to manage impacts" and press ahead with their published drought plans, including measures like hosepipe bans. It stressed that "essential supplies of water are safe."
Human-induced climate change
Satellite images from July released by NASA showed dried-up brown areas extending across most of southern England and up the northeastern coast.
The source of the River Thames has dried up and now starts from a point several miles downstream.
Meetings of the National Drought Group are convened by the Environment Agency, which monitors water levels in rivers and ground water.
The group is made up of senior decision-makers from the government and water companies, along with other affected groups such as farmers.
The Met Office on Tuesday issued an amber warning of "extreme heat" in parts of England and Wales Thursday to Sunday, predicting possible impacts on health, transport and infrastructure.
Temperatures were expected to peak in the mid-30s Celsius on Friday and the weekend, after which some showers and thunderstorms were forecast.
The National Climate Information Centre said that such high temperatures in the UK were only possible due to human-induced climate change.