Having a sister and son born on Groundhog’s day, It is important in my family. But......
The correlation seems to be with frontal movements.
If the front has passed, it will be clear and cold. If the front is just passing, it will be warmer but cloudy. The correlation prediction seems to be that if the day is clear there will be three more such frontal movements and six weeks of winter resulting from the cold trough. If cloudy the number of fronts till the trough recedes northward may be only two.
Like wooly worms, there is no real correlation.
Our family has a birthday on the day after “Candlemas Day”
We've had fun with it