Note: NOAA evaluated only animals with at least 20 years of recorded predictions. Accuracy shows how often each prediction matched real March temperature outcomes.
YouTooShallLose on
Since he’s the most accurate
From the news: New York City’s resident groundhog, Staten Island Chuck, saw his shadow early Monday — meaning six more weeks of dreaded wintry weather.
In case any one was wondering
USAFacts on
It’s Groundhog Day, again.
Figured I’d take a break from posting government spending data and get to the real hard-hitting stuff. This is a very important chart about groundhogs (and a tortoise and a prairie dog statue).
When I set out, I wrongly assumed Punxsatawney Phil was the only weather-predicting groundhog. It turns out there are a ton of groundhogs doing this, and Phil is actually pretty awful at it.
[NOAA](https://www.noaa.gov/heritage/stories/grading-groundhogs) looked at Groundhog Day predictions and compared them to actual March temperatures over the past 20 years. Only animals with at least 20 years of recorded predictions made the cut. Here’s how Phil fared:
The results:
* Phil gets it right 35% of the time, tied for last among qualified groundhogs
* He’s worse than several taxidermied groundhogs
* Worse than a mystery animal presumed to be a groundhog
* Worse than a prairie dog statue
* Only Mojave Max, a tortoise, performs worse
Meanwhile, Staten Island Chuck (formally Charles G. Hogg) clocks in at 85% accuracy.
Earlier today, both Phil and Chuck saw their shadows. So do with that what you will.
EDIT: Big news. In the time since I made this chart, NOAA updated their page with 2025 data. And Lander Lil (a literal statue of a prairie dog) has taken over the second place!
>In a stunning upset, prairie dog statue Lander Lil has overtaken General Beauregard Lee for the number two spot! Several other groundhogs improved their accuracy ratings, but not enough to make big changes in the rankings.
gemeloso on
The definition of “spring” doesn’t really make sense to me here. How much do temps have to match March to be considered spring?
Veeb on
Oh man, call me an ignorant European but I thought there was only one official groundhog.
Swoah on
What’s the split on the current Staten Island Chuck and the one that was brutally murdered by the former mayor in 2014
NadaBurner on
What do you mean west virginia has literally never seen their beloved mascot and it’s still in the top 5 for accuracy
minimalcation on
Phil is completely washed since his movie
bonbon367 on
If you had 19 people flip a coin 19 times and then graphed how often each person flipped “heads” it’d probably look a lot like this.
There is only one Groundhog and apparently he sucks at his job, get it together Phil.
CrimsonStorm on
Fun visualization!
I smell some p-hacking going on here, though 🙂 If you squint, it looks like the distribution of accuracy is pretty normal. I’d enjoy digging into the data more, but one thing I can’t figure out is how a “correct” prediction is defined. My best guess from ([https://www.ncei.noaa.gov/news/what-will-punxsutawney-phils-six-week-weather-prediction-be](https://www.ncei.noaa.gov/news/what-will-punxsutawney-phils-six-week-weather-prediction-be)) is that “early Spring” is defined as “March temperatures are above average”, which would mean that it should be an even 50/50 split (ignoring the effects of climate change).
So then a coin flip would be expected to be correct 50% of the time. Though, of course, “cloudy” vs “sunny” isn’t a 50/50 chance either and varies from place to place…
I’m not a statistician, so that’s as far as I can get without pulling out a textbook, but I’d love to see someone else do more with that.
qwigoqwaga on
I was curious what the odds of some of these were (I’d expect most to be much closer to 50%!), so based on the binomial distribution assuming 20 years of data, the 35% and 65% ones have about a 13% probability of occurring by chance, so everything in that range is probably just random chance. 25% and 75% are a 2% chance, which is less common. Those 80%+ ones are less than a 1% chance though!
farsightxr20 on
This looks suspiciously like a normal distribution centered around 50%…
FearMyPony on
Phil gives a bad name to the surprisingly wide field of rodent-based meteorology.
Also how does a Taxidermied Groundhog (and a statue) predict the weather? The source article doesn’t really explain that part.
notacanuckskibum on
Missing Lucy the Lobster, but then this seems to be a USA only list.
Chippings on
Mojave Max is actually pretty accurate if you just do the opposite of what he says.
OrangeDit on
Oh, Phil…
ntstockman on
Hey everyone, Punxsatawney Phil’s a great big phony!
om_steadily on
25% accuracy on a binary problem is actually 75% accuracy, if you just ask the question differently.
big_redwood on
Do they all use the same method to predict spring?
DameKumquat on
The lifespan of a groundhog is typically 2-3 years, maybe up to 6, in the wild, though up to 12-14 in captivity.
So are these groundhog clans, or random hogs found in a local area each year, or what?
Tankninja1 on
Punxsutawney Phil is washed
Its_not_him on
Just don’t ask Gen Beauregard Lee what his great grandparents were doing in the early 1860s…
baconator81 on
What is the definition of “spring” though? Does the average temperature need to exceed a certain threshold to be called “spring” ?
pangeapedestrian on
this is m favourite graph ever.
wordnerdette on
I’m bummed not to see Wiarton Willie (the Canadian groundhog here). Then again, in my partof Canada, the 6 more weeks of winter doesn’t make much sense. OF COURSE we’ll have six more weeks. The question is whether we’ll have 10 more weeks.
TijuanaJohnson on
Here in Nebraska we had Unadilla Bill for a little while
thestarkknight on
Where’s Wiarton Willy in Ontario, Canada
manofredearth on
So, did Woodstock Willy play Punxsutawney Phil, seeing as how that’s where Groundhog Day was filmed?
phejster on
Betteridge’s Law of Headlines says no.
Meanteenbirder on
I think Staten Island Chuck shouldn’t count by this metric since canonically, Mayor Bill DeBlasio killed him
preyforkevin on
Chuck is more accurate than any meteorologist could wish to be.
Luke5119 on
That Punxatawney fuck is only right 1/3 the time?
Reachforthesky777 on
I know Holtsville Hal – he takes bribes! It’s a Big Spring con-job!
LeftOn4ya on
Needs to get reposted in /r/Damnthatsinteresting and other interesting/science subs
_Lucille_ on
Most of them are less accurate than a statue…
rock374 on
Mojave max is arguable 75% accurate putting him in third place if you just flip his prediction
captainthepuggle on
How Phil does worse than the 3 other (dead) PA groundhogs is wild.
Neuroware on
it’s like they say, even a dead woodchuck is right half the time
Edit: Guess Bert’s only been at it for 14 years, but still a pretty good track record!
slackcastermage on
Wooooow. BALZAC BILLY doesn’t even make the cut. Imagine spending your whole life providing this wonderful service for us mere humans, and not even being recognized by the international organizations that oversees small marsupials that check the weather on Feb 1.
Come on folks. I bet Billy puts these stats to shame!
Edit: and he has way more than 20 years of recorded prediction.
cowlinator on
Once you get significantly below 50%, you’re back to being a good predictor.
People just have to invert your answer.
Like, an oracle that always lies is still very useful (when there’s only 2 choices).
ABAFBAASD on
To be fair, it’s not the groundhogs that doing the actual predictions. It’s really just humans observing sunshine and predicting accordingly.
45 Comments
Source: [National Oceanic and Atmospheric Administration](https://www.noaa.gov/heritage/stories/grading-groundhogs) using groundhogs listed on [groundhog-day.com](https://groundhog-day.com/groundhogs-in-usa)
Tools: Datawrapper, Illustrator
Note: NOAA evaluated only animals with at least 20 years of recorded predictions. Accuracy shows how often each prediction matched real March temperature outcomes.
Since he’s the most accurate
From the news: New York City’s resident groundhog, Staten Island Chuck, saw his shadow early Monday — meaning six more weeks of dreaded wintry weather.
In case any one was wondering
It’s Groundhog Day, again.
Figured I’d take a break from posting government spending data and get to the real hard-hitting stuff. This is a very important chart about groundhogs (and a tortoise and a prairie dog statue).
When I set out, I wrongly assumed Punxsatawney Phil was the only weather-predicting groundhog. It turns out there are a ton of groundhogs doing this, and Phil is actually pretty awful at it.
[NOAA](https://www.noaa.gov/heritage/stories/grading-groundhogs) looked at Groundhog Day predictions and compared them to actual March temperatures over the past 20 years. Only animals with at least 20 years of recorded predictions made the cut. Here’s how Phil fared:
The results:
* Phil gets it right 35% of the time, tied for last among qualified groundhogs
* He’s worse than several taxidermied groundhogs
* Worse than a mystery animal presumed to be a groundhog
* Worse than a prairie dog statue
* Only Mojave Max, a tortoise, performs worse
Meanwhile, Staten Island Chuck (formally Charles G. Hogg) clocks in at 85% accuracy.
Earlier today, both Phil and Chuck saw their shadows. So do with that what you will.
EDIT: Big news. In the time since I made this chart, NOAA updated their page with 2025 data. And Lander Lil (a literal statue of a prairie dog) has taken over the second place!
>In a stunning upset, prairie dog statue Lander Lil has overtaken General Beauregard Lee for the number two spot! Several other groundhogs improved their accuracy ratings, but not enough to make big changes in the rankings.
The definition of “spring” doesn’t really make sense to me here. How much do temps have to match March to be considered spring?
Oh man, call me an ignorant European but I thought there was only one official groundhog.
What’s the split on the current Staten Island Chuck and the one that was brutally murdered by the former mayor in 2014
What do you mean west virginia has literally never seen their beloved mascot and it’s still in the top 5 for accuracy
Phil is completely washed since his movie
If you had 19 people flip a coin 19 times and then graphed how often each person flipped “heads” it’d probably look a lot like this.
Still a cute tradition.
local groundhog Shubenacadie Sam is about 50%
[https://en.wikipedia.org/wiki/Shubenacadie_Sam](https://en.wikipedia.org/wiki/Shubenacadie_Sam)
There is only one Groundhog and apparently he sucks at his job, get it together Phil.
Fun visualization!
I smell some p-hacking going on here, though 🙂 If you squint, it looks like the distribution of accuracy is pretty normal. I’d enjoy digging into the data more, but one thing I can’t figure out is how a “correct” prediction is defined. My best guess from ([https://www.ncei.noaa.gov/news/what-will-punxsutawney-phils-six-week-weather-prediction-be](https://www.ncei.noaa.gov/news/what-will-punxsutawney-phils-six-week-weather-prediction-be)) is that “early Spring” is defined as “March temperatures are above average”, which would mean that it should be an even 50/50 split (ignoring the effects of climate change).
So then a coin flip would be expected to be correct 50% of the time. Though, of course, “cloudy” vs “sunny” isn’t a 50/50 chance either and varies from place to place…
I’m not a statistician, so that’s as far as I can get without pulling out a textbook, but I’d love to see someone else do more with that.
I was curious what the odds of some of these were (I’d expect most to be much closer to 50%!), so based on the binomial distribution assuming 20 years of data, the 35% and 65% ones have about a 13% probability of occurring by chance, so everything in that range is probably just random chance. 25% and 75% are a 2% chance, which is less common. Those 80%+ ones are less than a 1% chance though!
This looks suspiciously like a normal distribution centered around 50%…
Phil gives a bad name to the surprisingly wide field of rodent-based meteorology.
Also how does a Taxidermied Groundhog (and a statue) predict the weather? The source article doesn’t really explain that part.
Missing Lucy the Lobster, but then this seems to be a USA only list.
Mojave Max is actually pretty accurate if you just do the opposite of what he says.
Oh, Phil…
Hey everyone, Punxsatawney Phil’s a great big phony!
25% accuracy on a binary problem is actually 75% accuracy, if you just ask the question differently.
Do they all use the same method to predict spring?
The lifespan of a groundhog is typically 2-3 years, maybe up to 6, in the wild, though up to 12-14 in captivity.
So are these groundhog clans, or random hogs found in a local area each year, or what?
Punxsutawney Phil is washed
Just don’t ask Gen Beauregard Lee what his great grandparents were doing in the early 1860s…
What is the definition of “spring” though? Does the average temperature need to exceed a certain threshold to be called “spring” ?
this is m favourite graph ever.
I’m bummed not to see Wiarton Willie (the Canadian groundhog here). Then again, in my partof Canada, the 6 more weeks of winter doesn’t make much sense. OF COURSE we’ll have six more weeks. The question is whether we’ll have 10 more weeks.
Here in Nebraska we had Unadilla Bill for a little while
Where’s Wiarton Willy in Ontario, Canada
So, did Woodstock Willy play Punxsutawney Phil, seeing as how that’s where Groundhog Day was filmed?
Betteridge’s Law of Headlines says no.
I think Staten Island Chuck shouldn’t count by this metric since canonically, Mayor Bill DeBlasio killed him
Chuck is more accurate than any meteorologist could wish to be.
That Punxatawney fuck is only right 1/3 the time?
I know Holtsville Hal – he takes bribes! It’s a Big Spring con-job!
Needs to get reposted in /r/Damnthatsinteresting and other interesting/science subs
Most of them are less accurate than a statue…
Mojave max is arguable 75% accurate putting him in third place if you just flip his prediction
How Phil does worse than the 3 other (dead) PA groundhogs is wild.
it’s like they say, even a dead woodchuck is right half the time
Y’all are missing Buffalo Bert! 100% correct prediction! [https://groundhog-day.com/groundhogs/buffalo-bert/predictions](https://groundhog-day.com/groundhogs/buffalo-bert/predictions)
Edit: Guess Bert’s only been at it for 14 years, but still a pretty good track record!
Wooooow. BALZAC BILLY doesn’t even make the cut. Imagine spending your whole life providing this wonderful service for us mere humans, and not even being recognized by the international organizations that oversees small marsupials that check the weather on Feb 1.
Come on folks. I bet Billy puts these stats to shame!
Edit: and he has way more than 20 years of recorded prediction.
Once you get significantly below 50%, you’re back to being a good predictor.
People just have to invert your answer.
Like, an oracle that always lies is still very useful (when there’s only 2 choices).
To be fair, it’s not the groundhogs that doing the actual predictions. It’s really just humans observing sunshine and predicting accordingly.
I didn’t know there was more than one place.
Only legit one for me is Punxsutawney