https://www.kcrg.com/content/news/WWC-Saturday-is-Groundhog-Day-505229961.html
European immigrants to North America found a large number of groundhogs when they arrived, and so the groundhog was tasked with continuing this tradition and predicting the arrival of spring. The tradition is that, if a groundhog sees its shadow on February 2nd winter will last another six weeks. If he does not see his shadow, spring will arrive soon.