John Wheeler: Here is why snow makes it colder
A ground white with snow is really a ground that is reflecting most of the white sunlight that shines on it.
FARGO — Most people probably have a sense that snow on the ground makes it colder without knowing why. The reason is the white color. Snow is made of ice crystals, and while ice is generally translucent, snowflake crystals bend, bounce and mix all the light rays around so that it comes right back out again as white. This means a ground white with snow is really a ground that is reflecting most of the white sunlight that shines on it.
Solar radiation, however, is not just those rays that bring light, and the long wave radiation from the sun that brings heat to Earth is also reflected by snow. Another source of heat is from the ground below. Snow on the ground insulates the air above from that warmth, and the white color of snow also gives a boost to that kind of long wave radiation emanating from the Earth. Snow is a cold weather double whammy.