The Met Office has indicated that a third heatwave of the year is likely to arrive in the coming days, though it will not reach the extreme temperatures recorded last month. The UK's hottest June day was recorded on 24 June, when temperatures hit 35.7C in Surrey, breaking the previous record of 35.6C set in Hampshire in 1976.
Marine Heatwave Intensifying
In an update on 3 July, the Met Office warned that a 'long-lasting UK marine heatwave' could reach extreme levels next week. Sea temperatures are currently 2C warmer than average, with local anomalies of up to 5C off parts of the Welsh and English coasts. These elevated temperatures have developed rapidly, partly due to last week's atmospheric heatwave, and could intensify further as settled, sunny weather returns.
If the warm weather persists, the sea surface will have limited opportunity to cool, potentially pushing the marine heatwave to Category 4, classified as 'extreme'—a level rarely recorded in UK waters.
Inland Temperatures
Inland temperatures are forecast to rise again next week, with parts of England potentially reaching the low 30s Celsius. However, the likelihood of reaching the extreme temperatures and humidity of late June is low. Honor Criswick, a meteorologist at the Met Office, told the Manchester Evening News: 'Heatwave criteria is likely to be met by midweek in parts of the south. However, at present we are not expecting a repeat of the exceptional heat and humidity experienced in June; this is more typical summer hot weather.'
Overnight minima will also be above average, particularly in urban areas, but Criswick noted it 'should not be nearly as oppressive as some nights were in June.'
Cold Water Shock Warning
Despite rising water temperatures, the Met Office warns that cold water shock remains a risk. Holly Clements, Met Office Head of Warnings and Guidance, said: 'It is vital for the public to understand that although sea-surface temperatures are currently well above average in many coastal locations, this does not avoid the risk of cold-water shock. With warmer weather approaching, and even with marine heatwave conditions, it’s important to remember that the water around the UK is still cold. Entering it unexpectedly can lead to cold-water shock.'
The Met Office advises choosing RNLI lifeguarded beaches and swimming between red and yellow flags. In a coastal emergency, call 999 for the coastguard.
Tragically, on Monday, the body of a 15-year-old boy was recovered from water at Clifton Country Park after a major police search, just 24 hours after another 15-year-old boy's body was recovered from a reservoir in Tameside.
