Temperatures hit 42.3°C (108°F) at St James’s Park on Thursday, setting a new June heat record for London and slamming the southeast with a red extreme‑heat warning.
That blistering high was the hottest June day ever recorded in the capital, eclipsing the previous mark of 40.8°C set in 2019.
Why does this matter?
The red warning forces schools, hospitals and transport operators to activate heat‑health plans, and the electricity grid braces for peak demand.
But meteorologists say the worst is over. Elizabeth Rizzinni, a senior forecaster at the Met Office, notes a pulse of cooler, drier air is already sliding eastward from the Atlantic.
What happens next?
By Friday night, temperatures are expected to dip back into the mid‑20s across most of the southeast, while the red warning will be lifted for the majority of the region.
That relief comes with a caveat: the western counties – Cornwall, Devon and parts of Wales – will still wrestle with lingering highs of 30°C as the cold front skirts northern England.
For commuters, the shift means fewer delays on the Underground and less strain on bus fleets, which have been forced to run with reduced capacity to protect staff from heat‑related illness.
For vulnerable populations – the elderly, young children and those with chronic conditions – the cooling trend reduces the risk of heatstroke and dehydration, but warnings remain in place until nightfall on Saturday.
Businesses also feel the impact. Retail footfall surged 12% on Thursday as shoppers fled indoor air‑conditioning, but sales are likely to flatten as the heat eases.
Energy suppliers anticipate a 5% fall in demand compared with the peak on Thursday, easing pressure on the national grid and lowering wholesale power prices.
While the red warning eases, climate experts warn that such extreme June spikes are becoming the new normal. The Met Office’s own data show a 30% rise in the frequency of red‑level heat warnings over the past decade.
For now, residents can breathe a little easier, but the record reminds us that summer heatwaves are here to stay.
Stay tuned for the latest forecasts and health advice as the cooler air settles across the country.
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