The light has changed.
I don't know how to describe it, exactly, but the sunlight seems sunnier.
The ice is melting. Around the edges of the ice on the walk or the driveway, there's a perpetual darkness from the water melting underneath. Some places even give a satisfying crunch when you walk on them. OK, the driveway is still a skating rink, but now it's a skating rink with a big spot of bare pavement.
Spring is coming.