Britain's soggy summers will become warmer and drier, and London could experience scorching heat waves by late this century, a government-backed report on climate change said Thursday.
The study outlines three scenarios for climate change, based on high, medium and low global levels of greenhouse gas emissions.
The report said the medium emissions scenario, to which the world is currently closest, would see summer temperatures in Britain rise by about 4 C (7.2 F) by 2080.
Rainfall is projected to decrease in summer and increase in winter, bringing a greater chance of both drought and floods.
"Rainfall overall over the year will stay pretty much the same, but there will be increases in the winter and decreases in the summer," said Vicky Pope, head of climate-change advice for Britain's weather-forecasting service, the Met Office.
Pope said that by the 2080s London could see temperatures hit 41 C (106 F) on hot summer days.
The study is Britain's most comprehensive set of climate projections since 2002.
The report said that even if strong measures are taken to cut carbon emissions, greenhouse gases already in the atmosphere will make summer temperatures in southern England 2.3 C (4 F) hotter than now by the 2040s.
Environment Secretary Hilary Benn said the report showed climate change would "transform the way we live."
"These projections show us both the future we need to avoid and the future we need to plan for," Benn said.
He said government and infrastructure organizations such as Network Rail, the national electricity grid and the Environment Agency should be obliged to tell the public what they were doing to plan for the changes.