This winter, I think, is going to be challenging for me as a bike commuter in ways that prior winters have not. As with any endeavor, though, I will adapt. I hope.
Over the past two winters of commuting, I've built a fairly solid sense of what to wear for certain conditions. The problem is that each year my gear closet changes a bit and I get new bits and baubs that I have to experiment with.
Advice for riding in the winter - gear considerations
First, winter riding is, as we know, a different beast than that nice bike path ride in the summer. It does take some gear to be able to safely and comfortably ride in the winter.
But get the thought out your head that you have to go drop two week's wages at REI. While my gear has slowly evolved to use more and more cycling specific items, some of the best gear I've gotten has been from thrift stores and has been non-specific, or gear for other sporting pursuits.
That said - here's my list of layers for various conditions:
Head - Buff over ears and helmet
Hands - standard bike gloves (currently Fox Ranger)
Feet - cycling shoes and light fleece socks
Bottom - chamois short, Novara Windwall or Tempest pants (Tempest better for lower end of temp scale)
Top - poly sleeveless shirt, poly tee, merino jersey or North Face Apex lightweight poly jacket (Note: merino jersey was a steel at 9 bucks at my local thrift and one of my favorite pieces of gear)
Pretty much the same as the 40s, but I will throw on a pair of Outdoor Research Versaliner gloves and may wear a lightweight wool sock once it dips below freezing.
I add a long sleeved poly tee over the standard poly tee and favor the North Face jacket or in the lower 20s I'll throw on my REI Windflyte jacket. On the bottom I will go with the Windwall pants with a mid-weight pair of tights. On my hands I'll wear the Versaliner gloves, often with the shells that they come with to block wind. On my head I'll either double up my buff or switch over to a fleece skill cap in the lower temps. Feet - in the past I'd move to a Keen winter boot with wool socks. This winter I think I will try using my cycling shoes with a neoprene cover and wool socks to see how low I can go.
Head - REI windproof skull cap, buff around neck
Hands - Black Diamond Guide Glove outer shell over Versaliner liners
Feet - Keen winter boots, midweight wool socks with lightweight poly liner sock
Bottom - chamois short, light merino base layer tight, Windwall pant
Top - merino or poly base layer shirt, REI Windflyte shirt, REI Windflyte jacket (pit vents full open, generally)
Same as above, with the addition of another light layer top and bottom and chaning the Versaliner liners out for the Black Diamond liners that came with the gloves
Same as above - change to a heavyweight sock
Same as above, substitute second light layer for second midweight layer on top, close the pit zips
Substitute second midweight layer for second heavyweight layer
Ain't been there yet.
Sometimes, when it is in the single digits and snowing I will wear ski goggles to help keep my eyes from freezing over, though those tend to present a different set of challenges. I also, sometimes, start the ride with a buff over my mouth and nose, but even down into the -20s - the coldest weather at which I have ridden, I tend to leave my face exposed - apart from what is covered by my beard. I tend to overheat anytime I have my mouth and nose covered.