“Steam” almost surely isn’t the right word. Regardless, the photograph you see here, although you might not guess it, is of one of the world’s largest bodies of fresh water, Lake Superior. The air temperature is about -15 F. That steam/fog/mist/whatever-you-call-it is literally billowing off the surface of the open water, which has to be itself hovering right around the freezing point – so probably at a balmy 33 or 34 degrees. You wouldn’t think water that temperature could “steam,” but consider that at that temperature it is more than 50 degrees warmer than the air, and that heat energy is flowing into the great vacuum that is January in northern Minnesota.
Just another of the delights of a northern winter.