Hail is precipitation of small balls or pieces of ice with a diameter ranging from 5 to 50 mm or sometimes more, falling either separately or agglomerated into irregular lumps. On the other hand, the formation of ice particles over a
large area is called frost. If the dew point is below freezing point, the dew will not condense into water drops but will accumulate on earth's surface in the form of small white ice particles as frost.