[jseutter]

I commuted by bike during winter and found that I could handle temperatures down to -12C. Below that I couldn't keep my toes and fingers warm with mittens and booties. I had to trade off between adding layers to my legs and arms and sweating like crazy to provide enough warm blood to my hands and feet, or I'd wear the right amount for my legs and arms and my hands and feet would lose feeling.

I'm tempted to try it again this winter with battery powered hand warmers on my hands and feet, and handlebar mitts to keep the wind off my mittens.

Another important factor is the length of your ride. It takes a while to cool off, so a 15 minute ride may be fine while an hour long ride is miserable.