One of the truly American holidays, if it can be called that, is Groundhog's Day. The history behind Groundhog's day stretches back to the 1700's in Pennsylvania when the Pennsylvannia Dutch settlers used a badger as a weather predictor instead of the groundhog.
Ancient times stated that a hibernating animal could predict the coming weather by its emergence from its hole or cave. The tradition was brought over from Europe and bears a resemblance to Candlemas, a Catholic holiday from Medieval times.
Another holiday that Groundhog's day resembles is known as Iombolc, a Pagan holiday and celebration that celebrated the turning of the Celtic calendar. It was celebrated on February 1st and involved weather forecasting too. In England, it is always noted if rain falls on July 15th or St. Swithun's Day. A day similar to Groundhog's day, this day says that if it's raining that day, it will rain again for the next 40 days and 40 nights.
The legend states that if the groundhog comes out of his hole and sees his shadow on Groundhog's day, he will run back in and there will be six more weeks of winter. However, if he doesn't see his shadow, he will stay out and there will be an early Spring.
Any way you look at it, there is always six more weeks of winter, according to the calendar, after Groundhog's Day. According to statistics, the groundhog sees his shadow about 80% of the time.
These days, celebrations of Groundhog's in Punxsutawney, PA, draw crowds of up to 40,000 people. Lilburn, GA houses General Beauregard Lee while Jimmy the Groundhog from Sun Prairie, WI is considered the most legitimate ground hog as he's listed on the Congressional Record and Sun Prairie is considered the Groundhog Capital of the World.
An interesting note about Groundhog's Day is that Alaska does not celebrate it. Instead, February 2nd is noted as Marmot Day due to the lack of groundhogs in the state. The bill was signed in 2009 by then governor Sarah Palin.