Hot weather will continue across the UK on Sunday with possible highs of 31C as the country moves past the peak of its third heatwave this year.
Temperatures are forecast to dip slightly on Sunday before a cooler change on Monday that will bring "heavy spells of rain" for many areas, the Met Office said.
Amber heat health alerts remain in place for the Midlands, southern and eastern England until 9:00 on Monday.
On Saturday Scotland, Northern Ireland and Wales all recorded their warmest day of the year so far, while England saw a temperature high of 33.1C in Ross-on-Wye, Herefordshire.
Aviemore in the Scottish Highlands recorded a temperature of 32.2C - the first time Scotland has exceeded 30C since June 2023, according to the Met Office.
In Northern Ireland, there was a high of 30C in Magilligan, Londonderry - the first time that temperature has been reached since July 2022, the weather service said, adding that in Wales, Cardiff's Bute Park reached 33.1C.
The amber heat health alerts have been issued for six regions of England - the West Midlands, East Midlands, South East, South West, London and East of England.
Amber alerts mean weather impacts are likely to be felt across the whole health service, according to the UK Health Security Agency (UKHSA).
It warns of possible health impacts across the wider population, including a potential increase in the risk to health of people aged 65 and over, or those with pre-existing health conditions, as well as a rise in deaths for the over 65 age group.
Less severe yellow health warnings are in place until 9:00 on Monday for the North East, North West and Yorkshire and The Humber.
The latest heatwave has led to hosepipe bans being declared for millions of people in Yorkshire, Kent and Sussex.
This can mean restrictions on certain activities like watering gardens, washing cars, or filling up paddling pools - and those who break the ban could face a fine.
In Scotland, an "extreme" wildfire warning is in effect across much of the country with crews battling a blaze in Perth.
Firefighters in Surrey were also battling a wildfire to the south of Farnham which had grown to eight hectares as of Saturday evening.
The Surrey Fire and Rescue Service have told the public to avoid the area and urged nearby residents to close windows and doors.
The heat has also affected sporting events, with Wimbledon fans braving close to the hottest women's finals day at the tennis championship.
Temperatures hit 31C in Wimbledon, south-west London, as Iga Swiatek beat Amanda Anisimova in the women's singles final.
Sunday's men's finals day will see a cooler shift to 29C as the intense heat begins to ease, which will make conditions more comfortable for fans and players.
According to the Met Office, "the heatwave will begin to breakdown" from Sunday, and Monday will see showers developing across many parts of the UK.
"If you're not a fan of the heat, temperatures will be falling away but also bringing some heavy spells of rain, or welcome rainfall, for many of us," Met Office meteorologist Kathryn Chalk said.
The heatwave is expected to end for most on Monday, as cooler Atlantic air brings temperatures closer to the seasonal average for much of the UK.
The changed weather pattern will also bring rain to some areas, including those where rain has been seriously lacking recently.
However, those in the south-east of England may have to wait until Tuesday for some respite from the heat, with temperatures set to remain around 27C or 28C on Monday.
While linking climate change with specific individual extreme weather events can be difficult, scientists say that climate change is generally making heatwaves hotter, longer and more frequent.
Three summer heatwaves in quick succession after an unusually warm spring suggests climate change is having some effect on 2025's weather - impacting not just humans but wildlife as well.
