And unless you've been both housebound and had your internet connection cut off, you're probably also heard some idiot smugly asking "whatever happened to 'global warming', then?" (Or, as the Daily Mash delicately puts it, "Britain Trapped Under Two Feet of Global Warming Bullshit".)

I do not like this argument.
I do not like it because it sounds suspiciously like an ad hoc justification; that is to say, it is not properly falsifiable*. Flood, drought or blizzard, no matter what odd events happen, it could be viewed under this line of reasoning as evidence of climate change — in fact, the only thing that would falsify this would be for the weather to remain uniformly dull and predictable — and in the UK, that in and of itself would be viewed as unusual.
Now I know how climate change denialists think, because I was a little slow to accept the evidence myself — and indeed, I retain a small mental devil's advocate about the issue to this day. To the denialists, climate change is unscientific, a matter of religious conviction rather than evidential reasoning, and arguments like the above will only bolster their sense of smug, self-satisfied cynicism.
Instead, stick to the basics. Whether it's the Gulf Stream, solar flares, weather nymphs, or just random fluctuation, Britain's having some cold winters. So what? Global temperatures have been steadily rising for the last half century, and in the face of that, local yearly fluctuations just aren't relevant.
* If you have not read that essay, please do, it's a very influential one in the history of the philosophy of science, and yet fairly easy to follow!