A lot of people do not like riding in Winter time for obvious reasons, but it's really not that bad. With a little extra precautions you can by just fine.
GEAR - Wear the proper gear. Depending on your distance and weather, you may opt for something as simple as a jacket or as complex as full rain gear. If you live in the Pacific Northwest as I do, you know how essential rain gear can be. I am huge fan of Showers Pass and highly recommend their jackets and convertible pants.No doubt the gear can be $$$, but you'll break-even on your return after 1 season of riding. Two other essentials in my arsenal are a) booties aka shoe covers & b) bottom baselayer aka tights. The first keeps your feet warm and dry and the second keeps your butt and legs warm and dry. Both of these items are really nice-to-haves BUT they make riding much more enjoyable in winter.
As an example, here is my regular every-day winter gear:
Rain jacket
Convertible Rain Pants
Full tights for under 45F.
Booties.
Baselayer under my jacket.
Waterproof gloves. Another MUST for those with long soggy commutes in the PNW.
Waterproof backpack. Another MUST if located in a rainy place.
Regular old winter hat.
