For the first month of 2012, I biked 153 miles. Again, I think this is the first time I’ve ever biked in a January, so I feel pretty good about it.
Certainly, the mild winter we’ve been having helps. According to my (shoddy) record-keeping, the median temperature for rides have been in the 30s, which have been comfortable for me, so I guess I’m adequately layered. The coldest temperature I’ve biked in so far was 18 F. This was a quick trip to the Metro station in the early morning. The cold air stung my face, but the rest of my body felt relatively fine. I think that if I did a prolonged ride at that temperature, I would not be happy, but I found I could stand it for a short commute.
I suppose the conclusion is that the lowest temperature I would venture out for a ride would depend on the duration of the ride. Sounds obvious, but at least I’m on my way to determining my own threshold.