Concerning the Value of Groundhog Day · 5:31pm Mar 15th, 2017
Now, you may think, this is a bit late, no? But this wasn't actually inspired by Groundhog Day, nor by the movie about that day (which I haven't seen, anyway), but by Admiral Biscuit's excellent story Silver Glow's Journal, in which a pegasus exchange student got acquainted with an odd human tradition that went against everything her weatherpony training had taught her.
Unlike the poor pony in the story, I did realize that weather predictions given by a sleepy woodchuck were not to be taken too seriously, and my ponderings on that subject condensed into this poem:
Concerning the Value of Groundhog Day
By Nyerguds
Oh it's just a tradition
Based on old superstition
You won't risk extradition
By finding it dumb,
So just make it your mission
To avoid all derision
Go ahead, make a wish and
Enjoy all the fun.
But in case you are fishin'
For some truth in the vision
Of a groundhog's decision
As it sees the first sun,
Then I'll make the admission
There is not much precision
In the assumed position
Of that old groundhog's bum.
(With salutes to Tom Lehrer, whose style undoubtedly influenced this 
)
"So how long do we have to wait here?" hissed Luna to her sister, keeping her voice down in order not to draw attention from the rest of the crowd.
"No more than another hour or two," whispered Celestia back. "Have a little respect for their tradition, Luna. The ceremony of Groundhog Determination is a very ancient tradition of these earth ponies."
"Only two centuries," whispered Luna. "Hardly a blip. What happens if the rodent doesn't come out of its den?"
"Early spring," whispered Celestia. "I keep the sun up a little longer during the days so the weather warms up. It's a delightful time, with--"
There was an ear-splitting screech and a fat groundhog fairly exploded out of the rough hole in the ground. He darted back and forth, finally landing on his rump with a faint hiss of an extinguished fire and a small trail of smoke fading away from his panicked flight.
"Huzzah!" declared Luna into the resulting silence. "Six more weeks of winter!"
As far as weather prediction I'm pretty sure nothing is reliable. Least of all, a calendar. Next Monday is the first day of Spring? Really? Then why are the drifts so high I get my riding lawnmower stuck, and why am I waiting for a professional snow removal service to come clear my driveway?
Another sign of Spring, as reliable as the groundhog, is the robin. The robins return means Spring, right? I can hear robins calling in my yard, over the sound of the gale force winds. They sound miserable.
It used to be a truism that if you had a brown Christmas you would get a white Easter. I don't actually remember Christmas being that warm.
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Well somebody was clearly tired of waiting
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Nowadays, we get nothing but that, and we call it Global Warming
(and it's not even warm Christmas; just cold and wet.)
I take back what I said about the robins sounding miserable. They sound as if they are in shock.