While, unfortunately, the groundhog is not blessed with the uncanny ability to predict (or even bring about) shorter or longer seasons, there is some scientific thought about what abilities groundhogs do have when it comes to predicting or sensing changes in the weather.

As the end of January draws near, a certain holiday draws closer: Groundhog Day. On February 2nd, the famous Punxsawtaney Phil will be brought out for the masses to see if he will predict a longer winter, or a fast approaching spring. As you may know, his predictions are tied to whether or not he sees his shadow.

Th e history of Groundhog Day

But before we get into any of the science that could explain why groundhogs are believed to predict the season changes, let’s look at a short history of the legend itself. How did Groundhog Day come about—and why has it stuck around for so long? According to the official website of the Punxsutawney Groundhog Club, Groundhog Day is rooted in an old Christian tradition called Candelmas Day. On this day, on February 2nd, Christians would take candles to church to have them blessed in order to receive blessings and good fortune for the remainder of winter.

Over time, the interpretation of this day grew and changed, with animals being introduced such as the hedgehog in German lore. The hedgehog was thought to predict whether or not it would be a long winter or spring would come early. German settlers in the United States brought along this tradition but because there were no hedgehogs in the United States at that time, the settlers made do with groundhogs. In 1886, Groundhog Day appeared in a local paper and it has been celebrated every year since then.

Can groundhogs actua lly predict the weather?

As we mentioned, the popular legend is that if Punxsawtaney Phil sees his shadow, we all have to endure six more weeks of Winter past February 2nd. But, if he does n’t, then the weather should start to turn and we’ll soon have an early spring. While the origins of this tale aren’t rooted in fact, groundhogs do have a regular hibernation pattern. According to a professor of biology at Penn State, groundhogs’ hibernation usually end s around February 4th in Pennsylvania—a mere two days after Groundhog Day.

But, while the hibernation time of groundhogs can vary based on their location and latitude—with groundhogs in warm er climates, such as South Carolina, hibernating for much shorter periods of time than those up north—it has never been proven that groundhogs can actually predict the weather and season length. In fa ct, according to The Groundhog Club's records, Punxsawtaney Phil has only been right about a longer winter or coming spring less than 40% of the time. As with other animals, they have simply evolved t o be good at surviving the winters and climates in which they live, meaning their emergence from hibernation will often correspond with changing seasons.