I used to be a fair weather commuter. I stopped in November and start back after Daylight saving time. That was until last year when my car was having issue and driving the gas guzzler at 11 mpg was not an option.
It mostly the rain that used to bug me. That was until I found proper gear such as Shower Pass jacket, homade thigh chap rain cover and water resistant boots will keep me dry and comfy down to 35 degree while riding downhill.