Ice Fog

In Fairbanks, when the temperature falls lower than -40 degrees, the valley fills with a fog of ice crystals. These are frozen products from sources of moisture, such as evaporating warm water from hot springs or cooling ponds of power plants or moisture emanating from tail pipes in automobiles. Ice fog consists of poorly-formed crystals, due to the fact that evidently the water first condenses as a liquid, then rapidly cools before the system has time to form a well-ordered crystalline form.