Actually biking in snow is fine too as long as there isn’t too much of it. The real problems are around the melting point when everything melts a little bit during the day and three freezes over the night and thus you have to bike on ice. This can be fixed by studded tires but most don’t bother. Main issue for me for biking in the winter is the cold. Not really a problem anymore as I moved to Helsinki where it rarely is cold enough to be a problem.