This fine American tradition was little-known outside the US until Bill Murray relived the event over and over in the 1993 hit movieGroundhog Day. The term is now synonymous with events that repeat or seem familiar. The term is now synonymous with events that repeat or seem familiar. (Sorry - couldn't resist.)
But February 2 is indeed Groundhog Day, when Punxsutawney Phil, the mascot and most famous resident of the little town in Pennsylvania which gives him his name, emerges from his burrow on Gobbler's Knob and predicts the weather.
If he see his shadow, there's another 6 weeks of winter in store. If not, everything's going to be just peachy.
Here you can catch live updates from Gobbler's Knob as well as relive past predictions - which are (apparently) 100% accurate.
The Met Office please take note.
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