I just started riding again(did as a kid and in college) now at 53, started April '11 so I haven't found my limit yet. I've gathered some cool/cold weather gear to keep riding as long as I can. The lowest temperature so far I've ridden in was on Sunday where it started out at 36°F(2.2°C) and ended, after 20 miles, around 45°(7.2°)--plus a nasty wind chill factor since it was fairly breezy. I'm hoping I will be riding when it gets in the 20s F here. Generally, we get a 2 or 3 weeks during the year in the teens with highs in the 20s. Most of the time Winter in my area is in the 30s to the 70s--depending on where the front is over our area. Hampton roads is a winter wonderland--you never can predict what the winter temperatures will be in this land. This reminds me...I need to get a balaclava in preparation.