An amber heat health alert has been issued for some parts of the UK – days before what could be the hottest June day on record.
Sky News weather producer Joanna Robinson said highs of 34C are possible on Monday – with a 20% chance of beating the hottest day in June record of 35.6C from 1976.
Heatwave criteria are likely to be met in a few places on Sunday and Monday, mainly across parts of central and eastern England.
A heatwave is recorded when an area reaches a certain temperature – the level of which varies across the UK – for three consecutive days.
The UK Health Security Agency has issued an amber heat health alert for the East Midlands, east of England, London, South East and the South West.
It has also issued a yellow heat health alert for Yorkshire and The Humber and the West Midlands.
Both alerts begin at 12pm on Friday and end at 6pm on Tuesday July 1.
The alerts mean the predicted weather is “likely to cause significant impacts across health and social care services” – including a possible rise in deaths, particularly among those aged 65 and over or people with health conditions.
Before then, thunderstorms are forecast to sweep through the southeast of England on Thursday – while significant rainfall could hit the North and West of the country, the Met Office said.
The unsettled conditions look set to continue on Friday – with heavy rain possible in the West, while the east of England could remain dry, escaping with some sunny intervals.
Warm, humid air is set to linger in the South and East, with maximum temperatures of 27C in eastern England.
Parts of the South and East may also remain very warm, with highs potentially reaching 28C as the muggy air returns.
The wet conditions mean there has been a soggy start to this year’s Glastonbury music festival before highs of 30C are expected across the UK this weekend.
Warms nights have also been forecast for the weekend and going into next week – with temperatures set to be well above average across the UK.
Festivalgoers at this year’s Glastonbury. Pic: PA
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Robinson said there is some uncertainty over how quickly daytime temperatures will start to fall – but it is likely to happen from Tuesday.
She added that June is the first month of summer so higher temperatures are likely in July and August.
However, a rapid analysis from scientists at World Weather Attribution found that June heatwaves in the South East – where there would need to be three consecutive days of temperatures above 28C – are about 10 times more likely due to climate change compared with the cooler pre-industrial climate.
It comes after 2023 brought the hottest June on record with heatwaves also seen in June 2017 and June 2020.
Last Saturday was the hottest day of 2025 so far, with a provisional temperature of 33.2C recorded in Charlwood, Surrey.
In addition, the Met Office confirmed “many places” in England and “one or two areas” in Wales, including Cardiff, entered a heatwave last Friday.
