UK weather: Heatwave to ease next week as rain forecast, but 40C days becoming more likely, says Met Office

The Met Office’s long-range forecast covering June 23 to July 2 notes that the weather will turn more “changeable”, with occasional rain or showers, particularly in northwestern areas.

However, the recent spell of hot weather points to more intense and prolonged heatwaves in future, according to a new study by the Met Office. Met Office scientists say there is now more than a 20-fold increase in the likelihood of the UK experiencing extreme temperatures compared to the 1960s.

“The chance of exceeding 40°C has been rapidly increasing, and it is now over 20 times more likely than it was in the 1960s,” said Dr Gillian Kay, a senior scientist at the Met Office and lead author of the study published in the journal Weather. “We estimate a 50-50 chance of seeing a 40°C day again in the next 12 years. We also found that temperatures several degrees higher than we saw in July 2022 are possible in today’s climate.”

The report, titled Rapidly increasing chance of record UK summer temperatures, used the UNSEEN approach—a global climate modelling technique—to show how climate extremes have shifted over recent decades. In July 2022, the UK recorded its first ever temperature above 40°C when Coningsby, Lincolnshire hit 40.3°C. That heatwave, which formed part of Europe’s hottest summer on record, led to widespread wildfires, transport delays, and a spike in heat-related deaths.

Dr Nick Dunstone, a Met Office Science Fellow and co-author, added: “The well-known hot summer of 1976 had more than a fortnight above 28°C, which is a key heatwave threshold in southeast England. Our study finds that in today’s climate such conditions could persist for a month or more.”

Although short-term relief is on the way following a very warm weekend with highs around 30°C in parts of England, temperatures are expected to drop slightly from Monday (June 23), though they’ll remain above average in the southeast.

Further south and east, longer dry spells may persist under lingering high pressure, though forecasters say there is still a chance of isolated thunderstorms as warm continental air pushes in.

This comes as the UK will see the highest temperatures by Saturday (June 21), with much of the country expected to exceed the official heatwave threshold. In London, where the heatwave bar is 28°C, temperatures are forecast to hit 29°C on Thursday, rise to 31°C on Friday, and peak at 32°C on Saturday.

“Temperatures rising through the week will be home-grown conditions, where we get quite sunny weather, elevating temperatures,” said Met Office spokesperson Grahame Madge. “But as we get nearer to the weekend, that will receive a boost as we start to import warmer air from the south of Europe.”

A heatwave in the UK is officially recorded when specific regional temperature thresholds - ranging from 25°C to 28°C - are exceeded for three consecutive days. By the weekend, the heat is expected to push northwards, with places like Manchester and Newcastle enjoying highs in the upper 20s.

Saturday’s temperatures will surpass those in Barcelona and Lisbon, both forecast to reach 29°C, and even Nice, France, which is expected to see 30°C.