It was likely colder than that before I had gotten up as it was supposed to be -10° F. I do know, the wind is pretty chilly. My Mom's pipes were frozen, so all morning I was going around and trying to find where they were frozen. I've unthawed enough frozen pipes that I know how to tell if they're frozen, and they weren't frozen where I expected them to be. Instead, they were frozen much further down where a thread had let loose on a sewing job that was done several years ago to hold in the insulation. There's not really any I can do about the hole right now, but I got her pipes running again and she's trickling the water to keep them from freezing again.