Forecasters predict that temperatures could rise by 3C to 4C, making the West Country ideal for growing crops such as grapes, sweetcorn and sunflowers.
Meanwhile, commuters in London will be left sweltering as peak temperatures spiral as high as 41C.
However, climate change impacts are predicted to be so strong that, over decades, they are easier to predict than short-term changes.
Scotland and the north of England could also benefit with average winter temperatures rising by up to 2.6C.
The picture is similar in Wales where predicted temperature rises of up to 2.9C by 2080 could make Wales a more attractive tourist destination.
In East Anglia, by contrast, average annual temperatures could rise by 4C with summer rainfall decreasing by up to 60%, making what is now the agricultural breadbasket of England increasingly arid.
London is predicted to suffer the worst with a combination of global warming and the so-called urban heat-island effect pushing daytime summer temperatures to stiflingly hot peaks of 41C by 2080, compared with a maximum of 31C now.