
Homeschool Pop offers a good explanation of Groundhog Day for kids. The video explains the origins of the tradition, where it's celebrated, and a couple of fun facts about groundhogs.
Turn to SciShow Kids for more fun facts about groundhogs. The video teaches where groundhogs live, what they eat, and how they adapt to get through cold winters.
This video from Storm Shield explains a bit of meteorology that goes into whether or not the groundhog will see his or her shadow.
This video from CGP Grey deals mostly with the origin of the tradition. Like most CGP Grey videos there is a fair amount of snark included in the video so review it carefully before deciding if it's appropriate for your students.