Actually, Whitehorse is situated in a little micro-climate where we get the milder influence from the Pacific; we're also in a rain shadow so it's relatively dry here. But you don't have to go far to find deep snow and deeper temperatures (like, ten minutes up a snowmobile trail). And elsewhere in the Yukon it can get really bitter with high winds that combine for an unbelievable wind chill. I think a world record was set at Snag, Alaska, right on the border, a few decades ago, around -60. The Yukon Quest dogsled race from Whitehorse to Fairbanks is tougher than the Iditarod. We've lived all over the north in BC and Alberta and subzero temperatures, and I've never worried about steel getting brittle -- even a rifle barrel. But when it gets down to -40 and below, it's not fun out and Runs With Scissors has excellent advice.