Windchill is a very popular word these days. 20F, 30F, and 40F below windchill temperatures are all over the airwaves. But are these windchill temps really accurate and more importantly, useful?
Daniel Engber says no in Slate.com. He says windchill's popularity has more to do with big headlines and bravado, than useful science. I would tend to agree with him. Windchill is an estimate of how cold it may feel to you. Kinda subjective. -30F and -30 windchill aren't the same thing. Having been outside once a long time ago when it was -26F, I can say that -26 windchill doesn't feel nearly as cold. Windchill varies greatly because the wind doesn't blow consistently.
What I look at when I check the temp before hopping on my bike, is temp and windspeed. That tells me what to expect. I know what 5F and 10 miles an hour winds feels like, so make sure I have a little more protection from the wind. Two numbers and experiential learning.
Fact: The coldest temperature recorded Minnesota was -60F, in Tower back in 1996. The coldest estimated windchill temp was an estimated -71F in 1982 in northern Minnesota.