* ActorInspiredElement: The idea of Phil reading to Rita while she sleeps came from Creator/BillMurray. His wife drank too much champagne on their wedding night and fell asleep early, so Murray read aloud to her until he too fell asleep.
* AFIS100YearsSeries:
** AFIS100Years100Laughs: #34
** AFIS10Top10:
*** #8, Fantasy
* CaliforniaDoubling: Punxsutawney, Pennsylvania is represented by Woodstock, Illinois. The hotel across from the square [[spoiler:where Phil jumps to his death from the tower]]? That would be the Woodstock Opera House.
** And once you’ve figured that out, you’ll have no difficulty in guessing that the city road that gets closed off and forces the crew to turn around is actually in UsefulNotes/{{Chicago}} (Waukegan, to be exact), not Pittsburgh.
* CompletelyDifferentTitle: The Swedish title translates as "Monday the entire week". The movie, however, does not specify what day of the week it is supposed to be, and Groundhog Day (February 2) in 1993 was actually a Tuesday.
* CreatorBreakdown: Creator/BillMurray was going through a divorce during filming, which, coupled with arguments with Creator/HaroldRamis over what direction the movie should take, led to their friendship breaking down. They reconciled afterwards, however.
* CreativeDifferences: Creator/BillMurray and Creator/HaroldRamis disagreed on the tone of the film. Murray felt it should be philosophical, while Ramis thought it should be comedic.
* DuelingMovies: ''[[http://www.imdb.com/title/tt0106188/ 12:01]]'', though it's an expansion of the [[http://www.imdb.com/title/tt0098962/?ref_=tt_trv_cnn 1990 short of the same name]], ''12:01 PM''.
* EnforcedMethodActing:
** See MistakenForGay on the main page, and then realize that that scene was ''improvised'' by Bill Murray; Ned's reaction was largely genuine. StephenTobolowsky (who plays Ned) is a great character actor, and did plenty of improvisation in the film, too.
** As is usual for Bill Murray, when Rita slaps him, she really does hit him hard. Not surprising, since all of the abuse Murray suffered from Carol Kane in ''Film/{{Scrooged}}'' were real as well.
* NeverWorkWithChildrenOrAnimals: Creator/BillMurray was bitten by the groundhog twice during shooting. Murray had to have anti rabies injections because the bites were so severe.
* RealLifeRelative: The mayor is played by Creator/BillMurray's brother, Creator/BrianDoyleMurray.
* TheRedStapler: Since the film's release, the town of Punxatawney has now become a major tourist attraction.
* ShrugOfGod: How long Phil spent in the loop. Creator/HaroldRamis said it was ''10,000'' years, while Creator/BillMurray mentioned they discussed it and decided on "about ten years" (widely thought to be the "correct" answer).
* ThrowItIn:
** In the DVD commentary, Ramis claims that all he had planned for the scene in which Phil punches Ned Ryerson was just a simple faked punch. Toblowsky, who admits he can be a LargeHam sometimes, turned it into a full-on spin-and-stare-directly-into-the-camera-then-fall maneuver in reaction to the punch. And did so on every single take they tried. Eventually, Ramis just threw it in.
** After Phil smashes the radio, ''it keeps playing "I Got You, Babe"''. However, that wasn't ''supposed'' to happen. It was such a wonderful, dark moment that Ramis left it in.
** In the penultimate encounter between Connors and annoying insurance salesman Ned Ryerson, Murray was ad-libbing when he tells Ned, "I don't know where you're headed, but can you call in sick?" and causes Ned to run away.
** While filming the "Kidnapping Phil" scene, Murray spontaneously improvised the line "Don't drive angry, don't drive angry!" to cover the fact that the groundhog (which he was holding on his lap) was agitated and trying to escape by climbing over the steering wheel. A moment later the groundhog bit Murray's hand so badly he had to seek medical treatment.
* TypeCasting: Mostly Creator/BillMurray, alternately played straight and inverted during the course of the movie, but a couple of the others could be described as such too.
-->'''Creator/RogerEbert''': The Murray persona has become familiar without becoming tiring: The world is too much with him, he is a little smarter than everyone else, he has a detached melancholy, he is deeply suspicious of joy, he sees sincerity as a weapon that can be used against him, and yet he conceals emotional needs.
* UnintentionalPeriodPiece: WordOfGod stated that they sought to avert this by making sure there were no topical references. Yet Phil lighting a woman's cigarette in a restaurant dates the movie.
* WhatCouldHaveBeen:
** The original script featured the explanation for the unending loop and its escape clause,[[note]]it involved a curse by an ex reading a "how to do magic" book[[/note]] but they found by [[DoingInTheWizard leaving it out]] made the film more magical.
** They flirted with the idea of a DarkerAndEdgier film, by taking full advantage of the no consequences mentality, (major cruelty, murder etc.), but they decided not to, realizing a more light-hearted comedy would appeal more to the general audience.
** The original script had a HowWeGotHere structure, opening with showing Phil going through a day from beginning to end and leaving his knowledge of everything a mystery before flashing back to the start of the time loop.
** Apparently, one of the planned scripts showed that ''[[PlotTwist Rita]]'' was stuck in another time loop.
** Originally, when Phil snaps, he was supposed to murder the groundhog in its lair. This was changed to him kidnapping him, both because they feared the original plan was too close to ''Film/{{Caddyshack}}'', and because they feared it was too dark.
** Creator/HaroldRamis originally wanted Creator/TomHanks for the lead role, but decided against it, saying that Hanks was "too nice". Creator/ChevyChase, Creator/SteveMartin and Creator/JohnTravolta were also dismissed for this reason. Creator/MichaelKeaton was offered the role, but turned it down.
** Creator/ToriAmos was considered for Rita.

The ''Series/{{Jeopardy}}'' game [[JeopardyIntelligenceTest Phil watches over and over]] is the 1991 Tournament of Champions Semifinal game between Leslie Frates, Mark Pestronk, and Jim Scott (the eventual winner) that originally aired November 11, 1991.