How does Groundhog Day work? What happens if the groundhog sees its shadow?

The official start of spring is 20 March, but the weather doesn’t always follow the celestial calendar. For centuries, communities across North America have continued a tradition brought over from Europe to predict when the wintery weather will end.

For those who were unaware of Groundhog Day, the 1993 movie by the same name starring Bill Murray made people far and wide familiar with the annual tradition. Punxsutawney Phil, the other star of the movie, is the most famous groundhog forecaster, but how does he, and his peers, foresee the weather to come?

The Groundhog Day prediction depends on seeing a shadow

Groundhogs fatten themselves up in the fall before they lay down for a long winter’s sleep. In February, the males come out of their burrows to look for a mate prior to going back again to slumber some more. In the case of Groundhog Day, they’re given a little nudge to wake up.

A groundhog’s ability to divine the weather to come is based on whether or not he sees his shadow upon emerging from his dwelling. Clear skies bode ill for the weeks ahead as the groundhog will see his shadow and scurry back into his hovel meaning that there will be six more weeks of winter cold in store. Should the skies be cloudy, the opposite will occur, and spring will come early, at least according to superstition.

The earliest recorded mention of this come from the Punxsutawney Spirit newspaper from 1886, which read: “up to the time of going to press, the beast has not seen its shadow.” However, the first official Groundhog Day celebration was the following year. In most cities it is the mystical groundhog whispers into the mayor’s ear, Phil has a whole entourage called the “Inner Circle” who decipher his prediction.

How accurate are Punxsutawney Phil’s predictions?

The statistical probability of getting a coin toss right is 50 percent. But over his 135 years in the weather forecasting business, Punxsutawney Phil has been subpar in his predictions according to NOAA. Last year he got it half right when he predicted six more weeks of winter, even though the it was quite cloudy with a fair amount of snow falling.

But then again, he’s held to a high standard as the most well-known groundhog, tasked with predicting the weather for the entire nation when he only sees his shadow, or not, in Punxsutawney, Pennsylvania.

Other illustrious groundhogs

Phil isn’t the only Groundhog that makes an annual prediction of whether spring is just around the corner, or we’ll have to wait another six weeks for a reprieve from wintery weather. Across the US there are several other oracle Groundhogs, and although not as tenured Staten Island Chuck has had a better record getting the past ten out of eleven years right.

Chuck has had a couple of moments in the national spotlight, like the time he bit Mayor Michael Bloomberg in 2009. Or when he got tossed by Mayor Bill de Blasio in 2014, dying the following day, but his handlers said that it “appeared unlikely” it was the mayor’s fault.

There have been other memorable mishaps that have made national headlines such as Jimmy in Sun Prairie, Wisconsin in 2015. When he was held up to Mayor Jonathon Freud’s ear, he was apparently not happy to have been disturbed from his slumber and promptly took a bite.