Well, first you have to understand that it started out, in the US at least, when European immigrants wanted to take note of Hedgehog Day.

But the science of “6-more-weeks-of-winter” is: While animals obviously can’t predict the weather, hibernating males traditionally emerge sometime in February to gauge if they can start waking up their female counterparts to mate.

Okay, now to the history:

As the story goes,

National Hedgehog Day dates back to the ancient Romans, even if they might not have had a name for it yet. People then believed that if a hedgehog came out of hibernation on February 2 to a sunny day–causing him to see his shadow–he would return to his burrow, and winter would continue for another six weeks.

This belief persisted throughout the centuries in many different places and under other names, but always with the same idea. LIke:

• Christians celebrate “Candlemas Day” on February 2. They believe winter would continue if Candlemas Day were sunny. However, if Candlemas Day was cloudy, spring was near.
• Instead of relying on hedgehogs to predict the season, Germans had a tradition of watching badgers on their annual “Badger Day” every February 2nd.
• When European immigrants moved to America, they brought along the tradition to the New World, but–alas!–hedgehogs are not native to America! Badgers were not as commonly found there as in Germany, either!

This caused them to transfer the belief to another animal prevalent in the US, the groundhog. And thus, Groundhog Day was born. Therefore, National Hedgehog Day, Groundhog Day, Badger Day, and Candlemas Day are all ultimately about the same thing: the hopeful anticipation of spring and the end of the cold winter months. Or nudging your mate under the covers when her nose and other parts are cold.

Article excerpted from https://floofmania.com/hedgehog-day/ where there’s lots more fun stuff like Sonic the Hedgehog party food.