(I actually found this link under Weather, but felt it would be misleading to use that as the subject.)
There is more to Groundhog Day than meets the eye! The name came from the Delaware Indians, but the tradition is based on the German Candlemas Day.
http://weather.about.com/gi/dynamic/offsite.htm?site=http://www.stormfax.com/ghogday.htm

For the early Christians in Europe, it was the custom on Candlemas Day for clergy to bless candles and distribute them to the people in the dark of Winter. A lighted candle was placed in each window of the home. The day's weather continued to be important. If the sun came out February 2, halfway between Winter and Spring, it meant six more weeks of wintry weather.