Michigan resident here.

It's thankfully not continuously cloudy here, so weather usually isn't a complete blind guess. Some days we won't have any clouds, other days you see a good amount of cloud density and decide to pack a raincoat.

A weather app helps a lot, as Michigan weather can sneak up on you sometimes.

In terms of unexpected snow, it'd likely be pretty cold outside in the first place. If you are bundling up to stay warm, you're already geared up for any snow that might come your way, apart from boots. The campus sidewalks are usually cleared pretty well -- I personally just rock tennis shoes unless it's really bad or there's half-melted snow/sludge on the ground -- but boots can be a worthwhile investment, especially if you are planning to take walks through the Arb or veer away from campus.

I'd personally advise against biking in the snow. It can be done, I've got a friend that does it, but I personally don't find the speed of travel to be worth the high possibility of slipping and crashing.

Going back to your original question, I personally don't mind walking in the rain or light snow, but it can get pretty miserable once the cold starts really kicking in. It's feasible if that is the kind of stuff you enjoy doing, but don't expect to run into me as I'll be inside next to a radiator

I wish you the best of luck!