Another heatwave is set to sweep across parts of the UK during the weekend with 34C or more forecast.
Amber heat health alerts were posted for the east, South East and South West of England, as well as London, from 12pm on Thursday to run until 8pm on Tuesday.
Parts of the south and South East are likely to meet the heatwave threshold during the weekend and there is a 40% chance of exceeding the highest ever temperature for June, which is 35.6C set in 1957 and 1976, the Met Office said.
East Anglia could see 32C on Friday before the warm air temporarily shifts away from the UK leaving Saturday with a potential high of 28C.
But temperatures will rise again with parts of the south and South East expected to reach 32C on Sunday and then push up to or beyond 34C on Monday for some.
These temperatures are “pretty unusual even for the middle part of June”, Met Office meteorologist Alex Deakin said.
There is a small risk of the heat triggering thunderstorms in the South East and East Anglia on Sunday.
But the hot spell may not bring the “wall-to-wall sunshine and blue skies” of the May heatwave, deputy chief forecaster, Gregory Wolverson, said.
Cloud and fairly high humidity could make it feel “rather oppressive at times”, he added.
Temperature records were repeatedly broken during the May heatwave with 35.1C measured at Kew Gardens and 32.9C at Cardiff’s Bute Park.
There were 15 deaths in open water across the UK during May’s hot weather.
The UK Health Security Agency (UKHSA)’s amber health warning means an “increased demand” is likely to be placed on health and social care services, and could result in a rise in deaths.
Those aged 65 and over, as well as those with health conditions, will be most vulnerable, it said, though there may also be impacts on younger age groups.
Less severe yellow health alerts cover the East and West Midlands, warning of minor impacts on services.
The Met Office defines a heatwave as three consecutive days with daily maximum temperatures meeting or exceeding a location-specific heatwave temperature threshold.
Samantha Hughes, the national water safety partner at the RNLI, said: “With warmer weather approaching, it’s important to remember that the water is still cold.
“Entering it unexpectedly can lead to cold water shock, causing a sudden increase in breathing and heart rate, which may trigger panic.
“If you find yourself struggling in the water, remember to Float to Live: tilt your head back so your ears are submerged, relax and control your breathing.
“You may need to gently use your hands to help you stay afloat, and it’s ok if your legs sink – everyone floats differently.”
