According to folklore, if the groundhog sees its shadow on Groundhog Day, there will be six more weeks of winter. If the groundhog does not see its shadow, an early spring is expected. However, it should be noted that based on historical records, the predictions are accurate less than 40 percent of the time.
The tradition grew out of a belief in the Middle Ages that animals such as the badger and the bear interrupted their hibernation on February 2. If the weather was sunny, the animal would see its shadow, indicating six more weeks of winter. If the day was cloudy, it was taken as a sign that the following weeks would be mild, leading to an early spring. German immigrants to the United States carried the legend with them, and the groundhog came to be substituted for the badger.