I'll pretty much always ride when it is 40F or above and not raining or very windy. I'll occasionally ride when it is down to about 30F. Below that I will very rarely ride if it is a special event and I'll usually keep it short. I could easily push those limits downward by buying more appropriate winter riding gear, but for the few opportunities I would have to use it where I live, it has never made sense to spend the $ or take up the storage space in the house.