-40 is dangerously cold. It is no longer safe to have ANY skin exposed for any period of time. -40 is getting to the point where mercury will freeze. All moisture in the air freezes. It is too cold for it to snow. -40 is a dry and deadly cold.
When I was little and living in Bismarck, I got used to the fact that winters were bitterly cold. I mean cold of Biblical frostiness. I remember being glad when it snowed because the temperatures had to get UP to a point in order for it to snow. If however the snow was accompanied by wind it could so easily become a blizzard. The cold snap following a blizzard is always a dry, still, coldest sort of cold.
There is a reason that I remember that it is at -40 that the Fahrenheit and Centigrade scales converge. The reason I always remember this little fact is due to it actually dipping down to that temperature once when I was a kid.
I just got an e-mail from my mother telling me that the mercury has gone down to -40 at Embarrass, Minnesota, not too terribly far from International Falls (aka Frostbite Falls), Minnesota once again.
I don't live in North Dakota, Minnesota or even dear old Iowa anymore. I live in Scotland. Scotland is much further north than any of those states. I'm actually at the same latitude as Hudson Bay but due to the fact that I'm merely 10 miles from the Irish Sea, and our water is warmed by the North Atlantic Current of The Gulf Stream, it is always much warmer here than it is further inland.
So today, while I've been enjoying the 4th day in a row of lovely dry sunshine, my friends and family in the US are freezing their backsides off. Stay warm and stay inside you northern folks!