Digging into Groundhog Day

Last Updated (Tuesday, 09 February 2010 23:05) Written by Raymond Nakamura

My daughter was telling me all about Groundhog Day after kindergarten the other day.  I was thinking what a weird tradition it is, though perhaps it is no weirder than other marketing ploys dressed as traditions this month, like Valentine's Day, Lunar New Year, and of course, the Olympics.

Why do we have Groundhog Day?

In the lower Mainland, we are still waiting for winter to begin, never mind when it will end. In other places though, I suspect it has something to do with the February blahs or Seasonal Affective Disorder.

The first groundhog day took place in 1886, as a kind of media stunt. A newspaper editor orchestrated it in Punxsutawney, Pennsylvannia, home of the most famous meteorologically inclined groundhog, Punxsutawney Phil. 

In Canada, the most famous is Wiarton Willie, based in Ontario. This media stunt began in the 1950s with a fur hat, which was eventually replaced with an albino groundhog. The original Willie died back in 1999 while hibernating and has succeeded by other albino groundhogs. Punxsutawney Phil claims immortality.

Why is it on Feb. 2?

February 2, which is halfway between the astronomical start of winter (Dec. 21), the winter solstice when the night is the longest, and the start of spring (Mar. 21), the vernal equinox, when day and night have become equal.

Earlier celebrations on February 2 include the Celtic celebration Imbolc and the Christian Candlemas, which includes predictions for spring depending on the sun on that day. German settlers brought this custom to America. During the winter, if it's sunny, it's probably cold. Similarly, if a groundhog sees its shadow, winter is supposed to last another six weeks.

Why a Groundhog?

Various animals have been used for weather predictions in Europe including bears, badgers and hedgehogs, often related to their emergence from hibernation. 

Groundhogs (Marmota monax), also known as woodchucks and marmots, also hibernate. They have a wide distribution in North America.

How good are they at predicting the weather?

The accuracy of Canadian groundhogs is about 37% for the past 30 to 40 years. Based on the occurrence of sunny or cloudy days, this did not differ from chance. I could not find any data for paid meteorologists for six week periods. Of course, regardless of whether or not a groundhog sees its shadow, the official start of spring (Mar. 21) is about six weeks away.