Being from Vancouver, I'm used to rain. We only get a handful of days a year where it is coming down hard and it almost seems comical to ride. In Dec I've driven about once a week and ridden the rest of the days. It doesn't rain steadily very often so if I get wet in the morning it's often not raining on the way home.
I keep extra socks, tights and gloves at work so if I get soaked I can come home with dry clothes.
I won't ride on the weekend if it's raining.