UK should expect summers above 40°C in next decade, warns Met Office

Meteorologists say that in the next decade, summer daytime temperatures above 28°C could persist for more than a month, with spikes as high as 46.6°C possible under today’s climate conditions

By Madeleine Cuff

18 June 2025

Hot weather during UK summers is likely here to stay

HENRY NICHOLLS/AFP via Getty Images

The UK should urgently prepare for summer temperatures in excess of 40°C (104°F), according to the Met Office, the country’s national weather service, which warns the likelihood of extremely high summer temperatures is increasing rapidly as the climate warms.

Temperatures in Lincolnshire, in the east of the UK, hit a record 40.3°C (104.5°F) in July 2022, the highest level ever recorded in the country. The heatwave was made at least 10 times more likely by climate change, scientists said at the time.

Now researchers are warning such extremes won’t be an isolated event. The team, led by Gillian Kay at the Met Office, used a climate model to simulate more than 2500 UK summers to assess the kinds of extremes possible under 2023 climate conditions.

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The results show there is a 50 per cent likelihood of temperatures above 40°C occurring in the next 12 years, with the south and east of England most vulnerable to heat extremes. The chance of such extreme heat has risen rapidly in recent decades, increasing sixfold from the 1980s and almost tripling since 2000, the research shows.

Meanwhile, temperatures over 42°C (107.6°F) have a 1 per cent likelihood of occurring in any given year, and the maximum possible temperature the UK could see under current climate conditions is 46.6°C (115.9°F) – although this peak would be “exceedingly rare”, says Kay.

The simulations also give meteorologists a sense of the weather conditions needed to produce extreme heat in the UK. The most likely scenario is a persistent heatwave settling over Europe, with the hot air then moving across the UK’s south and east coasts. This week the Met Office warned a fresh heatwave loomed for the UK, triggered by intense warmth across the European continent.