On February 1, television weatherman Phil Connors reassures his Pittsburgh viewers that an approaching blizzard will miss Western Pennsylvania. Alongside his producer Rita Hanson and cameraman Larry, Phil travels to Punxsutawney for his annual coverage of the Groundhog Day festivities. Phil makes no secret of his contempt for the assignment, the small town, and the "hicks" who live there, asserting that he will soon be leaving his station for a new job.

A white house with green roof. It is set back from a lawn and surrounded by bare trees
A private home used for exteriors of the Cherry Street Inn, the fictional location in which Phil awakens every morning in the film.
On February 2, Phil awakens in the Cherry Tree Inn to Sonny & Cher's "I Got You Babe" playing on the clock radio. He gives a half-hearted performance reporting on the groundhog Punxsutawney Phil and the festivities. Contrary to Connors' prediction, the blizzard strikes the area, preventing all travel out of Punxsutawney, and although he desperately searches for a way to leave, he is eventually forced to spend the night in the town.

The next morning, Phil wakes once more to "I Got You Babe" and the same DJ banter on the radio. Phil experiences the previous day's events repeating exactly and believes he is experiencing déjà vu. He again unsuccessfully attempts to leave the town and retires to bed. When he awakes, it is again February 2. Phil gradually realizes that he is trapped in a time loop that no one else is aware of. He confides his situation to Rita, who directs him to a neurologist who in turn directs him to a psychologist; neither can explain his experiences. Phil gets drunk with locals Gus and Ralph and then leads police on a high-speed car chase before being arrested and imprisoned. The following morning, Phil awakens in the Cherry Tree Inn.

Realizing that there are no consequences for his actions, he begins spending loops indulging in binge eating, one-night stands, robbery, and other dangerous activities, using his increasing knowledge of the day's events and the town residents to manipulate circumstances to his advantage. Phil eventually focuses on seducing Rita, using the loops to learn more about her so that he can try to sleep with her. No matter what steps he takes, Rita rebuffs his advances, particularly when Phil tells her he loves her; Rita asserts that he does not even know her.

Phil gradually becomes depressed and desperate for a way to escape the loop. He commits suicide in a variety of ways, even kidnapping Punxsutawney Phil and driving them both off a cliff. Each time he awakens on February 2 to "I Got You Babe". He eventually tries to explain his situation to Rita again, using his detailed knowledge of the day to accurately predict events. Convinced, Rita spends the rest of that day's loop with Phil; she encourages him to think of the loops as a blessing instead of a curse. Lying on the bed together at night, Phil realizes that his feelings for Rita have become sincere. He wakes alone on February 2. Phil decides to use his knowledge of the loop to change himself and others: he saves people from deadly accidents and misfortunes, and learns to play the piano, sculpt ice, and speak French. Regardless of his actions, he is unable to save a homeless old man from death.

During one iteration of the loop, Phil reports on the Groundhog Day festivities with such eloquence that other news crews stop working to listen to his speech, amazing Rita. Phil continues his day helping the people of Punxsutawney. That night, Rita witnesses Phil's expert piano-playing skills as the adoring townsfolk regale her with stories of his good deeds. Impressed with Phil's apparent overnight transformation, Rita successfully bids for him at a charity bachelor auction. Phil carves an ice sculpture in Rita's image and tells her that no matter what happens, even if he is doomed to continue waking alone each morning forever, he wants her to know that he is finally happy because he loves her. They retire to Phil's room.

Phil wakes the next morning to "I Got You Babe", but finds Rita is still in bed with him and the radio banter has changed; it is now February 3rd. Phil tells Rita that he wants to live in Punxsutawney with her.