The temperature in London when I left was 14C - when I arrived in Edinburgh it was 7C. The reason for this? The many cooling towers around York. It seems to me the heat generated in the south of the country escapes through the cooling towers half way up and never quite makes it as far as Scotland.
I've back-blipped my week starting here
I think I might have this as my 2012 Challenge: Blur, there's a nice bit of motion blur bottom right.