I am. I'll bike down into the teens, but in rain/snow, I usually don't. I had an accident in the rain a while ago & it put the fear into me. I'm sure I'll get over it, but it took 2 months to heal & it wasn't worth the 2 mile ride I was taking home. I live in Maine, I was enjoying some rides the last couple of weeks, but we just got nailed again.
A lot of people ride through the bad weather though. More power to them.