According to Groundhog Day folklore, if the groundhog emerges from his burrow and sees his shadow, winter will last another six weeks. If the groundhog does not see his shadow, then spring will arrive early.
Although Groundhog day began to be celebrated in North America during the 18th and 19th centuries (most historians say it began in 1887) it has been celebrated in Europe for hundreds or thousands of years before that. The original weather wise animal was a badger or sacred bear but for convenience, or perhaps safety, the groundhog was chosen as the go to critter in North America.
Impartial estimates place the groundhog's accuracy between 35% and 41%.
A few states use their own groundhogs to celebrate the holiday rather than relying on Phil. Other weather oracles include General Beau Lee of Atlanta, Georgia, Sir Walter Wally from Raleigh, North Carolina, and Birmingham Bill from Birmingham, Alabama.
Groundhog Day falls on the 2nd of February for a reason. It’s what’s known as a “cross-quarter” day, meaning it falls at the midpoint between one season and another. In the case of February 2nd, it’s the cross-quarter day that falls between the winter solstice and the spring equinox, making it the ideal time to consider whether or not spring will arrive early.