What is cold for us here along the Front Range (the area running along the eastern side of the Rockies)? I would say it is what we've had for the last 4 days. Highs are about 8 degrees, and lows are dipping to 10 below at night. We have a few inches of snow on the ground, and the roads have ice patches - just enough to keep driving interesting.
While our house is pretty cozy and warm on the first floor, this kind of cold still finds a way to sneak in. I noticed our main door's dead bolt had white on it from frost. I snapped this picture of frost forming on the inside screws! They look like little marshmallows!!