I've been called crazy for years for riding my bike for commuting purposes, no mater the time of year. In the winter the use of crazy seems to have a higher percentage of usage in context to people riding their bikes. Crazy is as crazy does, I just want to ride and here is why.
People ask me all the time,"Why would you ride your bike in the winter? It's so cold" I ride my bike 350 day a year, putting weather on the back burner because we still drive, walk, and go about our lives regardless of what the weather is doing so why would I stop riding my bike because of it? Snow storms, flooding, cold below 0 F and monsoons are the exception for not riding my bike. Riding is a great way for me to wake up in the morning. Any time I have had to drive to work, due to bringing big things to the shop, I have found that I am not as alert because my heart rate hasn't been brought up and my body hasn't moved a great deal.
Today it was 15-20 F when I let my house this morning. Although I could have easily driven my car (the 8 blocks to work) I rode my bike because although it maybe cold, riding a bike keeps me warm. I don't have to bundle up as much as I would if I were walking.
So what do I wear to keep warm but not over heat? Every winter I try to find the right combo of base layer to jacket ratio that will keep me at the perfect temperature but truthfully it comes down to having a good wind breaker, great gloves (I use Pearl Izumi crab claws)something to keep the ears warm, and a scarf to keep the wind from chapping the face. From there I adjust my layers as needed for the temperature. If it is very cold, I'll put on some spandex pants under my jeans or skirt (yes, I still ride in skirts in the winter), and wearing shoes that the wind doesn't cut into as much.
So there is snow on the ground in the winter, big deal. I just ride a little slower, a little more cautiously, and I make sure my tires have the proper psi in them to give me the traction I need. I don't ride with nobby or studded tires in the winter because there really isn't a need for them unless one is planning on riding in some hardcore snow. Slicks do fine as long as you aren't trying to be a speed demon.
I'm not afraid of father winter, he can bring on the snow and the cold, I'm still going to ride because it's what makes me feel good and helps me do my part to ensure that Cache Valley air stays a little cleaner.