I am still riding BlackAdder, my city/cross/shopping bicycle the 8.5 km return trip to work each day. Yesterday was actually fairly mild and the return trip, in particular, was actually quite pleasant.
Today is a different story. Leaving the house, the temperature was -14C (6.8F) and there was a light 8 km/h (5 mph) wind blowing. However, once you start rolling on the pavement the Do-It-Yourself-Windchill goes up pretty fast, and I was doing some long stretches at 25 km/h (15.5 mph). The calculated windchill works out to around -38C (-31F).
When I got to the bike parking area at work, there was one other cyclist. Although I am ridiculously proud at having ridden in, I hope that the cold weather does not last too long!