What does a groundhog seeing its shadow traditionally predict?

Traditionally, a groundhog seeing its shadow predicts six more weeks of winter.

According to the folklore, the groundhog emerges on February 2. If bright sunshine lets it see a shadow, the animal supposedly retreats into its burrow, signaling that winter will continue for six weeks. If no shadow appears, the tradition predicts an early spring. The forecast is symbolic rather than a scientifically reliable weather method.

The custom developed from European Candlemas traditions, which linked clear skies with prolonged winter. German settlers in Pennsylvania transferred the practice to the groundhog, a familiar North American hibernating mammal. Punxsutawney Phil is the most famous participant, but many communities hold their own ceremonies with different groundhogs.

A frequent reversal is choosing “early spring” for the shadow result. In the standard American version of the tradition, early spring is the prediction when the groundhog does not see a shadow.