Hmm, I'm perplexed by the dismissive and borderline condescending responses here...
I know you all are trying to be humorous (failing I might add) but it is somewhat of a legitimate question and warrants a real response. Anyone who has used equipment prone to cracking in severely cold weather can attest to the possibility of increased risk of breakage during winter cold. For instance, I used to play lacrosse and it was well known that during particularly cold weather it was MUCH more likely that we would break the head of our stick when slapping other players sticks. The plastic got cold and was much more brittle. So really, it isn't silly to question if carbon becomes more brittle and prone to break during the winter as well....