Weather must not be devolved as I'm in Northern Ireland and I was out walking on Monday and it snowed, it hailed on me yesterday, it is freezing cold all day every day and so on. I've tried leaving my gas guzzling 4X4 running at night when I park it in the garage as the great prophets of the one true green religion ensure me that is causing things to heat up, it hasn't made any difference though so I think they must be wrong.
In saying that the last date I ever fished in snow was 18th May and it was a good deep fall of snow. It was a lovely sunny day and I remember lying on my back in the snow with the sun heating my face, pretty surreal really. I also spent a May week in the Hebrides for trout some years back and it snowed every day, I don't think I had a single fish.