Groundhog Day .
If the groundhog sees his shadow on February 2nd, expect six more weeks of winter.
The tradition derives from the Pennsylvania Dutch superstition that if a groundhog emerging from its burrow on this day sees its shadow due to clear weather, it will retreat to its den and winter will go on for six more weeks; if it does not see its shadow because of cloudiness, spring will arrive early. They brought the tradition from Germany, substituting a groundhog for the German tradition of a badger.
This tradition itself may be derived from lore that clear weather on the Christian festival of Candlemas forebodes a prolonged winter.
Punxsutawney, Pennsylvania began its annual celebration in 1887, which now features Punxsutawney Phil.