It said the country is likely to experience longer, drier summers that could worsen the risk of droughts.
The warmer weather patterns was due to increasing climate change, it added.
“Our research found that the largely ‘summer-like’ weather patterns - bringing drier conditions – will begin to extend into the start of autumn,” said Met Office scientist Daniel Cotterill.
“Although we don’t expect to see this shift in pattern imminently, a key finding from this study is that from the mid-2020s warmer and drier autumns following hotter and drier summers could increase drought risk.”
The prediction came after the UK sweltered for weeks this summer with a new record-high temperature of 40.3°C at Coningsby, Lincolnshire, in July.
Europe as a whole is in the grip of its worst drought in at least 500 years, according to the European Drought Observatory which emphasised that two-thirds of the Continent was recently in a state of alert or warning, reducing inland shipping, electricity production and the yields of certain crops.
Political leaders have been accused by scientists of failing to take sufficient action, including at the COP26 summit in Glasgow last autumn, to prevent catastrophic climate change.
Large parts of England have declared a drought in recent weeks.
The Met Office reached its conclusion that the changes were human-driven by comparing different emissions scenarios, which showed the effects were stronger when emissions were high.
It said summer-like conditions were expected to last longer and a 4-12 per cent reduction in rainfall in English regions was likely in the future in autumn.
The findings were presented in a paper titled "Future extension of the UK summer and its impact on autumn precipitation". It adds to a body of research showing seasonal changes caused by climate change.
Earlier this year a study said climate change was spurring earlier springs in North America and causing many birds to lay their eggs earlier in the year. Older studies have shown the same thing happening in Britain.