England and Wales have seen their driest July on record, provisional Met Office figures show.
Southern England saw its driest month ever recorded, in a series dating back to 1836, it added.
Last week the Met Office said the prolonged heat, abundant sunshine and an almost total absence of rainfall in some areas were making for a "truly exceptional" month.
It comes as health alerts are issued for most of England with temperatures expected to hit 35C on Monday.
More than half of England and the entirety of Wales is officially in drought.
Some 19 counties across England recorded effectively no rainfall - 1mm or less - across the whole of July, the Met Office figures show.
The conditions also delivered more hours of sunshine than average across large parts of the UK, driving a new record for solar power, the industry body Solar Energy UK said on Monday.
Britain harnessed a total of 3.2 terawatt-hours from the sun last month, amounting to 14.4% of all electricity - substantially higher than the previous monthly record of 12.4%, set only in May.
The dry conditions come after last year's drought summer, with the UK facing the impacts of more extreme weather fuelled by human-caused climate change, mostly as a result of burning fossil fuels.
The summer of extreme weather has seen two record-breaking heatwaves, in May and June, that led to more than 2,800 excess deaths, and two more heatwaves in July, which have fuelled drought and wildfires.
Drought is a highly complex state because it is influenced both by the weather and the way rainwater flows and is used by people once it falls on land.
Science has not yet proven a concrete link between drought and climate change in Britain. However, warmer air evaporates more moisture from the soil.
Scientists expect the UK's winters to become wetter and summers hotter and drier, as the climate warms.
Some 23 million customers are under hosepipe bans, and rivers and the natural environment are struggling with low water levels.
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Amber alerts, the second most serious, have been issued by the UK Health Security Agency for the East Midlands, East of England, South East and London regions for 48 hours from 9am on Monday.
Less severe yellow alerts are in place for the same period covering the North West, Yorkshire and The Humber, West Midlands and South West regions.
Rising temperatures bring health risks, the agency said, with greater demand for health care services by the vulnerable and an increase in risk to health for the over-65s or anyone with a pre-existing health condition.
A thunderstorm warning has been issued for Northern Ireland on Tuesday.
Heavy showers and thunderstorms will develop for parts of England and Wales as well, the Met Office said.
'Many farmers now on full winter rations'
The harvest has come early and farmers are warning of poor crop yields while livestock are already being fed winter feed.
Tom Bradshaw, president of the National Farmers' Union, said the hot weather is affecting potato harvests - and that more support is needed to help farmers "adapt to the changing climate".
He said: "About half of the UK crop is irrigated. That half is running out of water very, very quickly. The reservoirs are almost empty.
"There must be moisture in the ground to be able to harvest those potatoes. So we need to think about the resilience of our food system as a national priority."
Mr Bradshaw said it is an "atypical" summer, as we are now on the fifth heatwave, with notably dry conditions, and the lush grass of April, May and June is now a burnt brown colour.
He said that "many farmers are now on full winter rations, and it's only the beginning of August".
Mr Bradshaw added: "We want to adapt to the changing climate, but to do that, we need the support of government policy, building reservoirs on our farms to store the water."
(c) Sky News 2026: 'Truly exceptional': England and Wales see driest July on record, provisional Met Office figures show


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