I won't ride if there's snow/ice on the pavement. If it's below 40 degrees and raining hard, I won't ride, either. Nothing worse than being wet and cold.

It's never too cold to ride in dry conditions, so long as you layer correctly & use chemical hand/foot warmers. Only one thing is to remember that your gatorade might freeze, so bring along some Shot Bloks! When it is really hot, I just make sure I hydrate sufficiently and take it easy. I used to train for marathons in the worst of DC's heat/humidity, so riding a bike in it is much easier than running!!

SheFly is our official Queen of adverse conditions, going out in the dark when it's 15 degrees outside! She can ride on ice covered ponds, for crying out loud!!!!!!!