Who is Jack Frost?
Jack Frost is an imaginery character who appears in traditional stories and is supposed to trace the patterns made by frost. He represents extreme cold and probably originated in Scandinavia, where according to Norse mythology, Kari, god of the winds, had a son named Jokul or Frosti - Jokul meaning icicle and Frosti meaning frost.

  Father or Mother Frost?
In Russia, the frost is represented as a white old man, Father Frost, and in some German tales as Old Mother Frost.

Frost can be rated by an intensity level and because of the importance of frost formation to agriculture, its intensity is judged by the degree of its destructive effect upon different types of vegetation. Frost is described as being light, heavy or killing.

A black frost is a name given to a situation where low temperatures cause destruction of vegetation without the existence of frost crystals.