One of my good friends growing up went to college at the University of Alaska Fairbanks campus.
He told me once that they had an informal test for how cold the day was. Take a half a cup of coffee, stick it out the window (on the second or third floor of the dorm, as I recall), and turn the cup over. If a brown splotch appears in the snow below, it's not too cold. If a small hole appears where the chunk of iced coffee hits it, it's starting to get fairly cold. If nothing at all appears on the snow, it's definitely cold and you should bundle up well.