Groundhog Day, observed on February 2, is a traditional event intended to predict how much longer winter will last in the United States and Canada. According to folklore, if a groundhog emerges from its burrow and sees its shadow, there will be six more weeks of winter. If the groundhog does not see its shadow, an early spring is expected. Historical records indicate that the predictions are accurate less than 40 percent of the time.
The custom has its roots in a belief dating to the Middle Ages that certain animals, including the badger and the bear, emerged from hibernation on February 2. If it was a sunny day, the animal was thought to see its shadow, which was interpreted as a sign that winter would continue for six more weeks. A cloudy day was believed to signal milder weather and an early spring. The belief was brought to North America by German immigrants, and the groundhog came to be substituted for the badger.