Summer 2025 was warmest on record - and repeat is now 70 times more likely, Met Office says

The UK has just sizzled through its hottest summer on record, a phenomenon made 70 times more likely by climate change, the Met Office said today.

It beat the previous high set in 2018, and kicks the notoriously hot summer of 1976 into sixth place.

The persistent heat drove hosepipe bans, "nationally significant" water shortfalls, and even a "false autumn" in places.

The new provisional data found temperatures between 1 June and 31 August 2025 were 16.10C on average across the UK - much higher than the previous record of 15.76C in 2018.

The difference might sound small, but - as an average over a three-month period, including day and nighttime temperatures - is in fact substantial.

All the top five warmest summers have occurred since the year 2000, which the Met Office called a "clear sign of the UK's changing and warming climate".

Did autumn come early this year?

The heat gave rise to early signs of autumn, with blackberries ripening early and leaves turning brown and falling to the ground in August.

This so-called "false autumn" is not the early arrival of the next season, but a survival mechanism of trees and plants when stressed by extreme summer conditions.

They shed leaves and fruit ahead of schedule to conserve water and energy, especially the younger trees whose shallow roots can't access moisture further underground.

Kevin Martin from Kew Gardens called false autumns a "visible warning sign".

"Trees are remarkably resilient, but they are also long-lived organisms facing rapid environmental changes."

Was this summer warmer than 1976?

This summer was the hottest on record going back to 1884, and far warmer even than the memorably hot summer of 1976, which now trails in sixth place.

The Met Office's Dr Mark McCarthy said this shows how "what would have been seen as extremes in the past are becoming more common in our changing climate".

The summer of 1976 is remembered for its heatwave that lasted more than two weeks, and 16 days in total with temperatures over 32C.

Although 2025 has had just nine days of temperatures over 32C, what is "striking" about this summer is how consistently warm it was, the Met Office said.

Why was this summer so warm?

There were a number of factors that made it so warm, so persistently.

Lingering high pressure made for settled, sunny and warm weather, and fuelled four heatwaves.

It was also very dry, with about a quarter less rain than average for summer - though that varied by region. But it followed the driest spring in England for more than a century.

Dry ground holds less moisture that can evaporate: a process that usually cools things down.

And a marine heatwave sent sea temperatures on the surface well above average, with a knock-on impact on air temperatures.

Overnight temperatures were also high, keeping the average up.

What about climate change?

Climate change made a summer as hot or hotter than this year 70 times more likely, the Met Office said.

It adds another layer of heat on top of the other weather patterns that may have happened without humans changing the climate.

The UK is warming by roughly 0.25C per decade, and is already at least 1.24C warmer than the period between 1961-1990.

Without climate change, a summer like in 2025 would have happened about once in every 340 years. Now it's expected once in five years.