The Bill Murray comedy movie has become a classic since it was released in 1993.
But what many people don’t realise is that Groundhog Day is not just a fictional occurence and is an actual celebration in some places in America.
While it doesn’t mean anything much in the UK, on the same February day in the US thousands of people anxiously wait for the signal telling them what kind of weather they can expect in the coming weeks.
So, what is the day all about, what usually happens - and when is it this year?
Here’s everything you need to know.
What is a groundhog?
To understand the significance of groundhog day, you first need to understand what a groundhog is, since they don’t live over here.
Also known as a woodchuck, a groundhog is a rodent called the Marmota monax.
It’s related to the squirrel and looks a bit like an oversized guinea pig.
They are herbivores, eating green plants like dandelion and clover, and they live for six to eight years.
The animals are found in North America, eastern US, Canada and Alaska.
Groundhogs hibernate every winter, and they usually come out of their underground burrows at the beginning of February - when Groundhog Day occurs.
What is Groundhog Day?
The day comes from an ancient Germanic tale about a groundhog appearing from its burrow around the start of February.
If the groundhog emerges from its hibernation home on a clear or sunny day and sees its own shadow, it will be scared back into its burrow.
This occurrence signals another six weeks of a cold winter.
However, if it’s a cloudy day and the groundhog doesn't see its shadow, that means winter will end early and spring will soon begin.
The tradition stems from similar beliefs associated with Candlemas, the ancient Christian festival that marks the midpoint of winter.
Groundhog Day is also a common saying, meaning a situation in which a series of unwelcome events appear to be recurring in exactly the same way.
When is Groundhog Day 2021?
Groundhog Day falls on the same date each year - 2 February.
This date was chosen for the ceremony as it’s thought to be the midpoint of winter.
That means this year’s Groundhog Day is on Tuesday 2 February.
It is hosted online after sunrise on that date from 6am to 8am (Eastern).
How is it celebrated?
Although Groundhog Day is celebrated across North America, the observance originated in a small town called Punxsutawney in Pennsylvania in 1886.
This is where the largest celebrations take place - and also where the Bill Murray film is set.
In the town, Groundhog Day features a local celebrity - a rodent called Punxsutawney Phil, who is named after King Philip.
There’s a ceremony held at day break at a place called Gobbler’s Knob in the town.
Phil, being a special groundhog, is looked after year-round by the Punxsutawney Groundhog Club Inner Circle, who plan the yearly celebrations.
On 2 February, once he has emerged from his burrow, Phil supposedly tells the president of the club - the only person who is thought to understand “groundhogese” - his weather prediction.
The president then translates the message and the verdict is read out to the crowds and on live TV.
After the ceremony, people commonly have a meal and drink groundhog punch - a bizarre mixture of vodka, milk, eggs and orange juice.
Local legend has it that the same groundhog in the town has been making predictions for more than a century, as he drinks a magic elixir every summer which gives him seven more years of life.
Historically, Phil’s success rate for accurately predicting the weather is only around 40 per cent.
Other American cities also have their own special groundhogs, such as Chuck on New York’s Staten Island.
Unfortunately, due to the coronavirus pandemic, organisers of the 2021 celebration have said no visitors can attend the ceremony.
Phil’s fans will be able to view the live ceremony and prediction on TV and social media livestreams instead.
What happens in the film?
If you’re not in America but would like to celebrate Groundhog Day, you could do so by watching the Bill Murray film.
In the movie, which is based on the annual ceremony, the actor plays a self-centred weatherman who goes to the town of Punxsutawney for an assignment.
Yet, he wakes up the next morning and is horrified to realise that he’s reliving Groundhog Day over and over again.
Sky Cinema is showing the film on repeat on 2 February.