Why Do Groundhogs Really Emerge on February 2?

Caitlin Dempsey


Groundhog day is coming up on February 2. The legend goes that if a groundhog emerges from its den and sees its shadow, six more weeks of winter are coming. If not, then spring will arrive early.

How Did Groundhog Day Get Started?

The legend has had different iterations over the hundreds of years of its existence. Early February traditionally marked the beginning of the growing season across parts of Europe.

February 2, Candlemas day, marks the halfway point between the winter solstice and the spring equinox. The Candlemas celebration marked the anticipation of the planting of crops so a determination of a prolonged winter or an early spring was important.

Emerging hibernators was a natural choice of an indicator that spring was coming. In England and France, a bear was the symbol of an emerging spring, while in Germany it was a badger.

German immigrants to the United States in the 1800s substituted the lack of badgers in the Pennsylvania area with groundhogs and the tradition continued.

A groundhog standing in grass and eating the flower of a clover.
Groundhog. Photo: NPS, public domain.

Groundhogs Emerge for “Love” Not the Weather

The average date of groundhogs emerging from hibernate in southeastern Pennsylvania occurs around February 4th according to Stam Zervanos, Emeritus Professor of Biology, Pennsylvania State University. This timing fits in well with the local legend.

Unfortunately, the timing of the emergence of groundhogs as an indicator of weather is little more than a coincidence. The real reason groundhogs emerge, according to Zervanos, has more to do with Valentine’s Day.

In preparation for mating season in March, groundhogs emerge in early February to essential “date” or more scientifically, “reestablish the bonds necessary for mating and ensures that mating can then proceed without delay in early March.”

If “dating” in February and mating in March happens, then groundhog offspring will arrive in early April. This ensures the best chances of survival for the young groundhogs who need to be born not too early and not too late in order to take advantage of the start of food availability in May.

Two groundhogs sniffing each other's noses.
Normally territorial, groundhogs emerge from hibernation in early February to re-establish bonds in time for mating season in March. In this photo, a male groundhog (right) greets a female groundhog (left) after emerging from hibernation. Photo:  Stam Zervanos, Creative Commons

How Accurate Has Punxsutawney Phil Been?

Punxsutawney Phil is probably the most famous tradition of Groundhog Day. Every February 2 Punxsutawney, Pennsylvania holds a celebration that centers around a groundhog emerging from its temporary home in Gobbler’s Knob. If Punxsutawney Phil emerges from his hole and sees his shadow, he will return to his hole for six more weeks of winter.

Since 1887 Punxsutawney Phil has predicated more winter 77.6% of the time. According to NOAA, in the last ten years, Punxsutawney Phil has been correct 50% of the time.

Inforgraphic from NOAA showing how often Punxsutawney Phil has been correct in his weather predictions on Groundhogs Day.
Inforgraphic from NOAA showing how often Punxsutawney Phil has been correct in his weather predictions on Groundhog Day.


Wardle, H. N. (1919). Note on the Ground-Hog Myth and Its Origin. The Journal of American Folklore32(126), 521-522.

Candlemas/Groundhog Day. (n.d.). Retrieved from Candlemas/Groundhog Day. (n.d.). Retrieved from https://www.almanac.com/fact/candlemasgroundhog-day-its-no-accident-that-groundhog-holiday

Zervanos, S. (2015, February 2). Why do groundhogs emerge on February 2 if it’s not to predict the weather? Retrieved from https://theconversation.com/why-do-groundhogs-emerge-on-february-2-if-its-not-to-predict-the-weather-36376

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About the author
Caitlin Dempsey
Caitlin Dempsey is the editor of Geography Realm and holds a master's degree in Geography from UCLA as well as a Master of Library and Information Science (MLIS) from SJSU.

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