Unless there is any serious deterioration (and I know we've had snow at Easter before near Dundee) I'm swapping back at the beginning of March - the other day it was 13 degrees here indicated, and in conditions like these the braking feels squidgier than on the Rainsports although down around zero they feel very similar to Rainsports through the summer. Made the mistake of leaving the winters on my Yeti until late May a few years back owing to being too busy to do the switch and wore them down badly on the front outer shoulders - although the A2s do seem to be much lighter on tyres than the Yeti was.