Met Office issues amber warning for England and Wales from Thursday to Sunday.
Forecasters say London will reach 32C (90F) by the weekend.
The extreme heat warning covers portions of southern England and eastern Wales from Thursday to Sunday, affecting health, transportation, and infrastructure.
Level 3 Heat Health Alert will begin at noon today, with no rain forecast to ease the danger of drought, which has caused hosepipe restrictions and fire warnings.
Temperatures will hit 29C (84F) in London, 28C (82F) in Southampton, and 26C (79F) in Exeter on Tuesday.
The Met Office predicts temperatures to reach the low to mid-30s in central and southern UK on Thursday, although not as high as the record-breaking heat in July.
The UK Health Security Agency has issued a Level 3 Heat Health Alert for southern and central England from noon today until Saturday 13 August.
It encourages Britons to ‘watch out for others, particularly elderly individuals, small children and newborns, and those with underlying health concerns’
It also recommends people to ‘shut curtains on rooms that face the sun to make interior areas cooler’ and ‘drink lots of fluids, avoid excess alcohol, dress correctly for the weather, and slow down when it’s hot’
With months of low rain leaving the countryside and urban parks and gardens tinder-dry, several places are urging residents not to set fires or have barbecues.
Met Office’s fire severity index (FSI) is extremely high for much of England and Wales and will reach ‘exceptional’ by the weekend across a slice of England.
Tory leadership frontrunner Liz Truss has weighed in on hosepipe bans after two water companies warned others they may need to follow suit.
This follows the driest eight months from November to June since 1976 and the driest July on record for parts of southern and eastern England.
Ms Truss added, ‘We should be harsher on the water providers and there hasn’t been enough action to deal with these faulty pipes.’
My water company in dry Norfolk needs to be held accountable.
She told the Daily Express that hosepipe bans’should be a last option’ but that they appear to be a first choice rather than water suppliers fixing breaches.
Dr. Agostinho Sousa, Head of Extreme Events and Health Protection at UKHSA, stated, ‘Temperatures will feel quite warm again this week, especially in southern and central portions of the nation.’
‘Enjoy the warm weather safely, but remember that heat can affect health quickly.
‘Vulnerable persons, such as old people who live alone and those with health concerns, should be prepared for hot weather.
Staying hydrated, keeping cool, and preventing overheating are the most critical tips.
Climate change, caused by burning fossil fuels and other human activity, is increasing the chance of droughts, say scientists.
Climate change makes heatwaves more severe, frequent, and probable; this month’s record temperatures were ‘almost unthinkable’ without global warming.
When questioned about a hosepipe ban for London, government minister Paul Scully said it’s ‘always prudent’ to save water.
He continued, ‘But we’ll watch carefully because the more growth you have and the less rainfall there is, the less there is to go around and we’ve got to be cautious.’
Much of the UK may reach heatwave thresholds, which vary by region.
Scotland and Northern Ireland might exceed heatwave standards by Friday, forecasts warned.
The Met Office upped the temperature threshold for a declared heatwave in eight English counties to reflect the warming UK.
The warmest places are anticipated in central and southern England and Wales on Friday and Saturday, according to Met Office deputy chief meteorologist Tony Wardle.
Saturday might reach 35C or 36C.
‘Temperatures elsewhere will reach the mid 20s and low 30s Celsius later this week as high pressure builds across the UK.
Along with high daytime temperatures, mild evenings are forecast, with the mercury dropping to the low 20s Celsius in certain southern places.
Met Office predicts relatively short-lived showers in the North West.
Mr Wardles added, “Further south, which has experienced no rain for some time, dryness will persist through the week, providing little respite for parched areas, particularly in the South East.”
Richard Allan, a climate science professor at the University of Reading, said human-caused climate change worsens droughts.
A warmer atmosphere is thirstier and dries up the ground, while heatwaves worsen drought conditions. Ocean breezes can’t blow enough moisture over the land because continents are warming so quickly.
Uneven global warming may alter weather patterns and increase wet or dry spells.
Prof Allan claimed that human-caused climate change is exacerbating the global water cycle and changing weather patterns, leading to more severe droughts and floods.
Dr. Leslie Mabon, an environmental systems professor at The Open University, stated, ‘The drought danger in the UK is a reminder that we need to attack the issue at its source: lowering fossil fuel emissions to minimise disastrous climate change.’
‘Countries like the UK, which has a moderate climate and less experience with hot, dry periods, must prepare now to adapt to hotter weather.
This includes looking at our water infrastructure and deciding where to invest to be better prepared for hot periods.
Hosepipe restrictions might remain until October with no’meaningful rainfall’ anticipated as temperatures reach to 36C in several areas of England.
The Met Office predicts temperatures in the low to mid-30s across central and southern UK, although not as high as July’s record-breaking 40C.
The UK Health Security Agency has issued a heat health warning for southern and central England from Tuesday to Saturday.
An Atlantic weather system next week might cause a 10C temperature drop and more rain and thunderstorms. It won’t replace water supply.
Following the driest eight months from November to June since 1976 and the driest July on record for parts of southern and eastern England, two water companies have already announced hosepipe bans.
Southern Water has asked the Environment Agency for a six-month ‘drought permit’ to draw more water from the River Test, The Times reports.
The River Test’s daily flow was 2,500Ml in March but is now 450Ml.
Southern Water said the flow might drop to 365Ml this month, the permitted maximum for water removal.
A spokeswoman added, ‘The permission will last six months or until flows reach 500Ml per day for 21 days.’