The Pennsylvania rodent is the most famous of the furry weather forecasters for "Groundhog Day," an event with early roots in German folklore -- and rather more in US media showbiz.
According to legend, if Phil had not seen his shadow then spring would soon be on its way, bringing relief to a nation that has survived an especially harsh winter.
But instead, the groundhog purportedly announced: "That's not a football lying beside me,/ It's my shadow you see/ So, six more weeks of winter it shall be!"
The groundhog said he could not predict whether the Denver Broncos or the Seattle Seahawks would win the National Football League championship game.
Groundhog Day falls on February 2 each year, attracting large crowds to the little Pennyslvania town of Punxsutawney.
It started with a German tradition in which farmers closely monitored the animal's behaviour to make decisions about when their fields should be planted.
The town, which claims to have held its first Groundhog Day in the 1800s, is the undisputed headquarters for the unscientific experiment.
Last year, Punxsutawney Phil predicted an early spring.
