UK heat warning to ease as cooler air moves in from west

A red extreme heat warning stayed in force across the East of England, London and South East England on Friday, with hot, humid weather carrying risks to health, transport, energy, water supply and water safety. The warning ran from 00:00 to 21:00 on Friday 26 June 2026, as cooler air began edging in from the west.

Friday was still forecast to be punishingly hot, with London expected to reach 38C and overnight temperatures in some places failing to fall below 20C, creating tropical nights. This was the first time under the current warnings system that red extreme heat alerts had been issued for three consecutive days in the UK.

Serious illness or danger to life was highly likely for the general population, with substantial changes needed to working practices and daily routines. Hospitals, transport operators and other critical services were already dealing with the strain of extreme heat, while the warning also highlighted water safety risks as people looked for relief in rivers, lakes and coastal waters.

A strong area of high pressure over continental Europe was driving the heatwave, leaving the UK on the boundary between very warm continental air and cooler, more unsettled air to the northwest. That pattern kept the south-east as the hottest part of the country while the north-west stayed cooler, before the fresher air spread east.

Relief was expected to come gradually rather than abruptly. Bands of showers, including heavy and possibly thundery rain, were forecast to move east from Sunday into Tuesday, bringing much fresher conditions after the most intense heat had passed. Hot nights and stretched infrastructure could keep pressure on services and vulnerable residents into the cooling period.

The Met Office said June temperature records were in range, including the UK June record of 35.6C set in Southampton in 1976 and at Camden Square in 1957. The heatwave was part of a wider European event that had driven temperatures in Spain, France and Italy into the high 30s, with some places rising above 40C.