Britain will swelter in scorching 34C heat this weekend as a brutal heatwave grips large parts of the country — with health bosses warning people to stay indoors and brace for soaring temperatures until at least Tuesday. The UK Health Security Agency (UKHSA) has issued a yellow heat health alert for six regions, including London, the South East, South West, East and West Midlands, and East of England, warning of increased risk to vulnerable people and added strain on the NHS. The warning came into effect at 10am on July 9 and will remain in place until 10am on July 15.
Temperatures are forecast to climb through the week, peaking at 34°C in parts of southern England by Saturday, with minimal relief at night. Met Office data shows lows barely dipping below 15°C, raising the risk of sleep disruption and heat-related illness. A “stay indoors” message has been circulated by health chiefs urging people to avoid the hottest parts of the day — typically between 11am and 3pm — and to keep homes cool, stay hydrated, and check on the elderly or vulnerable.
The heatwave is being driven by a high-pressure system drawing hot air from Europe, locking in dry, stifling conditions across much of the country.
Forecasters warn that while July’s record high of 35.8°C (Cambridge, 2019) is unlikely to be broken, the prolonged nature of the heat poses significant public health concerns, with the Met Office urging people to guard against dehydration, heat exhaustion and heatstroke.
This marks the third significant heatwave of summer 2025, following spikes in June and early July.
On July 1, London reached 34.7°C, while parts of Surrey saw the mercury rise to 33.2°C during the UK’s hottest June on record.
According to climate scientists, such events are now two to five times more likely as global temperatures continue to rise.
The heatwave has prompted wildfire warnings, with bone-dry conditions raising the risk in southern England and Wales. Meanwhile, Yorkshire Water has confirmed a hosepipe ban will come into force on July 12, while Thames Water has warned that restrictions could soon follow across southeast England if reservoir levels continue to fall.
Despite the sizzling weekend forecast, a cooler westerly front is expected to arrive on Monday, bringing much-needed relief. The Met Office predicts highs will drop to around 24°C on Monday, before falling further on Tuesday with showers and overcast skies expected in many regions.
Nevertheless, temperatures will gradually return to near-average levels early next week, although some southern areas could remain warm for a time.