Today is the Feast of the Presentation, Candlemas and Groundhog Day
And they are all related...
Here is the official Groundhog Site.
The groundhog tradition stems from similar beliefs associated with Candlemas Day and the days of early Christians in Europe, and for centuries the custom was to have the clergy bless candles and distribute them to the people. Even then, it marked a milestone in the winter and the weather that day was important.
According to an old English song:
If Candlemas be fair and bright,
Come, Winter, have another flight;
If Candlemas brings clouds and rain,
Go Winter, and come not again.
According to an old Scotch couplet:
If Candlemas Day is bright and clear,
There'll be twa (two) winters in the year.
Another variation of the Scottish rhyme:
If Candlemas day be dry and fair,
The half o' winter to come and mair,
If Candlemas day be wet and foul,
The half of winter's gone at Yule.
The Roman legions, during the conquest of the northern country, supposedly brought this tradition to the Teutons, or Germans, who picked it up and concluded that if the sun made an appearance on Candlemas Day, an animal, the hedgehog, would cast a shadow, thus predicting six more weeks of bad weather, which they interpolated as the length of the "Second Winter."