Interestingly, in the winters the streets seem much cleaner much faster than the sidewalks. In fact, pedestrians get to deal with snow plowed off of the streets.

I know a few residents who bike to work from Cambridge to MGH (over the Longfellow bridge) year-round.

If you're used to riding in traffic, it's not really any riskier than other seasons -- they salt the roads heavily and tend to have the main ones pretty clear the day after a storm.

Probably the riskiest part (as a commuter) was that with shorter days, I was often riding home well after sunset.

The Hubway stations are removed before winter.

In Scandinavia people take the bike even in snow storms. Just put on winter tires and you're safe.

I commute on my bike all year long in Pittsburgh, and did do as well in Boston (Cambridge and Allston). It was actually easier in Boston as they're better at cleaning snow off the streets. It's perfectly possible with the right gear.

Ironically, many of the best cycling cities in the world have terrible winters. Montreal, Copenhagen, Dublin - not exactly tropical climates. They manage.