That Antarctica, the Arctic, Greenland and the frozen wastes of Siberia are covered in white comes as no surprise. But it is the extent to which the line dips down over the Northern Hemisphere that is so remarkable about the image.
The shroud of white stretches down from Alaska and sweeps through the Midwest and along to the Eastern seaboard. The bitter cold has reached as far as Texas and northern Mexico where in Ciudad Juarez temperatures today were expected to dip to minus 15C.
Lots of cool (haha) photos on that site.