BUT STILL OUTPERFORM STOCK ACCOUNT MANAGERS:

After dozens of grueling hours of investigation, FiveThirtyEight can confirm that Punxsutawney Phil is a charlatan. A groundbreaking analysis1 has revealed the Pennsylvania-based groundhog who makes annual predictions about the arrival of spring is not nearly as reliable a prognosticator as those close to him claim. Phil, arguably the world's most well-known rodent weather predictor, has been forecasting when spring will arrive annually on Groundhog Day since 1887. But when comparing his predictions to historical weather data, he's only right about a third of the time. [...]

In an effort to be generous in our interpretation (and following the lead of the National Oceanic and Atmospheric Administration's (NOAA) previous groundhog analysis), our analysis has an early spring bias -- only one month needs to have had an above-average temperature for a year to count as an early spring, even if it's only a slight increase in temperature. Though a half-degree above average is hardly a delightfully early eruption of spring by most standards, it qualifies by our metric.

If we look at Phil's predictions nationally (as Dunkel encouraged), they were accurate only 36 percent of the time (judging by national average temperatures). But how can just one marmot know a whole nation's weather? Looking at a more granular level -- by region -- doesn't help much. Phil's accuracy ranged from 50 percent in the Southwest and South to just 36 percent in the West. Even in the Northeast, where Phil's home state of Pennsylvania is located (and where one might expect him to best forecast weather patterns), he was only 39 percent accurate. That's similar to what other organizations have found about Phil's record, such as Time, the Washington Post and NOAA (though our analysis uses different weather data and compares Phil to other prognosticators). 

But perhaps -- perhaps! -- the accuracy of a soothsaying animal meteorologist doesn't matter. Michael Venos, a database administrator from Roxbury, New Jersey and the creator of countdowntogroundhogday.com -- a database of, among other things, animal prognosticators' historical predictions2 -- told FiveThirtyEight that Groundhog Day isn't about being right or wrong. It's about fun. 

"I don't know if I should say this, but I don't put a lot of stock in whatever they predict," Venos said. "To me it's definitely just the fun of the ceremony and finding out about all the different, strange [traditions]."

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