LONDON, June 21, 2025 — A sweltering heatwave sweeping across the UK is expected to peak on Saturday, with temperatures climbing as high as 34°C in some regions, while forecasters also warn of intense thunderstorms set to strike parts of northern England, the Midlands, and Wales.
The Met Office has issued a yellow weather warning for thunderstorms from 15:00 BST on Saturday through to 04:00 on Sunday. The combination of heat and mounting humidity is forecast to trigger torrential downpours, with potential for localised flash flooding, lightning, and large hail.
Much of the UK endured searing heat on Friday, with Scotland, Wales, and Northern Ireland all registering their warmest days of 2025 so far. Whitechurch in Pembrokeshire recorded 30.8°C, while Castlederg in Northern Ireland hit 29.5°C. Drumnadrochit in the Scottish Highlands reached 28.9°C.
England’s highest temperature was 32.2°C on Thursday, although Heathrow Airport saw a high of 29.5°C on Friday. Suffolk became the first region to officially declare a heatwave earlier this week, with London following suit on Friday after exceeding the 28°C threshold for three consecutive days.
With overnight temperatures lingering at uncomfortably high levels — still hovering around 24°C at 23:00 on Friday — some areas are facing what meteorologists call a “tropical night,” where lows do not dip below 20°C.
The UK Health Security Agency (UKHSA) has issued an amber heat-health alert across England, warning of sustained strain on healthcare services and increased risk of heat-related illness and death, particularly among the elderly and those with pre-existing conditions.
“This level of heat will impact all of us, even those who consider themselves fit and healthy,” said Dr Agostinho Sousa, Head of Extreme Events and Health Protection at the UKHSA. “It’s vital that we check in on vulnerable people and stay hydrated.”
As heat builds in from Western Europe, forecasters anticipate some relief on Sunday, with cooler air beginning to move in from the west. However, eastern England may still see overnight lows around 18°C. Temperatures will fall further into Monday before potentially rising again by the end of next week.
The Met Office reports that while this week’s heat is significant, it remains below the historic June high of 35.6°C recorded in 1976. Nevertheless, the frequency and intensity of such heatwaves are rising, a trend linked to human-induced climate change.
According to the World Weather Attribution group, the likelihood of 32°C temperatures in June has increased 100-fold since the pre-industrial era. A three-day June heatwave has shifted from being a once-in-50-year event to a one-in-five-year occurrence.
Meanwhile, the National Fire Chiefs Council (NFCC) reports a worrying surge in wildfires, with over 500 incidents in England and Wales this year — a 717% increase from the same period in 2024. NFCC Chair Phil Garrigan urged the public to be vigilant with outdoor activities, warning of “more frequent, intense, and dangerous” fire risks.
“This summer’s extreme heat is not an anomaly — it’s a warning,” said Ben Clarke, environmental policy researcher at Imperial College London. “With every fraction of a degree in global warming, the UK becomes more vulnerable to deadly heatwaves.”
