While we played (day 22) it started raining and then snow appeared on everything, the night of, the snow disappeared then the next day it started snowing but everything didn't get covered with snow.
So basically the snow appeared and disappeared suddenly.
I don't know if this is a bug, or if it's because it's only the beta. We've tried to play an offline game because we didn't have access to Internet and the world wouldn't start. I had to restart the whole game to start another game.