xkcd #3202: Groundhog Day Meaning
Title text:
Originally, the ceremony used a variety of rodents and mustelids, but over time most people agreed it made sense to standardize on a specific individual ground squirrel in Pennsylvania.
Transcript:
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Source: https://xkcd.com/3202/
Groundhog (Gr), a unit of uncertainty in weather predictions. The value of 1 Gr means the prediction is as good as pulling it out of a hat.