This morning was a balmy 0F when I left the house. It was actually quite a nice ride in. By the time I left the university, the temperature had dropped to about -15F with a -31F wind chill. Burrrrr. Wind chills are supposed to drop into the minus 40s this weekend, so I don't think I'll be venturing out on the bike (or probably much at all!).

I totally agree that temperature tolerance is a function of what you are used to. I'm much more acclimated to cold weather living in Saskatoon than I ever was when I lived in Michigan. I find that the dryness here also makes it feel less cold at the same temperature. The lack of humidity also makes summer heat much more bearable.