Saturday is provisionally the hottest day of the year so far in the UK, with a scorching 32.7C recorded in Heathrow, west London, the Met Office has said.
The UK has already sweltered through five days of temperatures above 30C in September for the first time, with that record likely to continue for another day before temperatures dip next week.
In addition to high daytime temperatures, it will remain uncomfortably warm overnight, only dipping to 24C.
Previously, the highest temperature of the year had been set on Thursday, with 32.6C recorded in Wisley, Surrey.
The UK Health Security Agency has issued an amber heat health alert, meaning weather impacts are likely to be felt across the health service, with those aged above 65 or those with pre-existing respiratory or cardiovascular disease at greater risk.
Meanwhile Mayor of London Sadiq Khan has issued an air pollution alert, the first since June, and urged Londoners to stop their engines idling and refrain from burning wood or garden waste.
“On Saturday, alongside the current high temperatures, we will also experience high levels of air pollution,” Mr Khan said.
“Pollution and heat can be a dangerous combination, which is why I’m urging Londoners to look after themselves, stop their engines idling and refrain from burning wood or garden waste, all of which contribute to high levels of pollution.
“This is particularly important in order to protect those who are most vulnerable and help us to build a safer and greener London for all.”
The Met Office is forecasting temperatures to reach 31C in London on Sunday before dropping to 25C on Monday, marking the end of a record sizzling week.
