Listen to this interview with chief scientific adviser Sir Mark Walport in which he describes the relationship between extreme weather and climate change (link below).
...we know that, statistically, in those parts of the world where there is rain there will be more rain, we know that as water levels rise there will be more flooding...This is, not to put too fine a point on it, unmitigated tosh. We "know" nothing about future rainfall. We have a hypothesis coming out of a very iffy set of computer models. This sort of claim, made without even the merest hint of uncertainty, is why people are so suspicious of the utterances of chief scientific advisers."