Continuity mistake: When Ned first calls out to Phil, the Gift Shoppe store behind him has a sign in the display window saying "OPEN SUNDAYS 12 to 4", and a white poster in the door window. The remaining three times Ned calls out to Phil with that background, the Open Sunday sign is gone, and the poster in the door has changed to a smaller red sign. Also, vehicle positions have changed slightly, and the black truck's tire sidewall on the left changes position between first and remaining scenes.
Continuity mistake: When the truck goes off the cliff in the quarry, we see it falling in a close shot, then it changes to a wider shot, except the driver's side mirror in the close shot is folded out, while in the wider shot it is folded in. The powder on the tires is also different.
Continuity mistake: In the opening scene Phil is doing a weather report and is wearing a wireless mic on his vest. When they go off-air he jumps up and two seconds later the wireless mic is gone, neither on his vest or in his hands. Taking off both the mic and the transmitter would take longer than two seconds.
Continuity mistake: Two chocolates are shown next to the alarm clock each time the clock is switched off or destroyed. They are in slightly different positions in every shot throughout the movie.
Factual error: Phil departs from the office right after the 5pm news. Punxsutawney over 90 minutes' drive from Pittsburgh. The sunset in Punxsutawney in early February is about 5.30pm, so by the time they get there it should be completely dark. But it's bright daylight, without even a hint of twilight.
Continuity mistake: When Phil looks out the window on the first Groundhog Day, he sees the right-turning truck outside the window just as the radio people shout "Groundhog Day", but on the first repeat of the day, the same scene outside the window occurs only after this exclamation is made. It couldn't be altered by him because he had just woken up.
Revealing mistake: When Phil drives the truck off the cliff, you can see right through the grill of the truck (meaning there is no radiator or engine), and the transmission is also missing, as you can see when the truck is falling upside down. Without an engine or transmission it would be hard to drive off a cliff.
Audio problem: At the party when Phil is playing the piano, there are several shots of the other band members. Multiple times they are seen playing their instruments, but they are never heard. The most obvious example is right before Phil finishes up his set. The saxophone guy is playing but you never hear it.
Continuity mistake: When Phil comes around the corner, just before meeting Ned, there are two women walking together in the background. The one in blue is holding a yellow sign upside down that says Phil (the groundhog, not the character). The first 3 days in a row they are together as they should be. On the fourth day and every day thereafter the woman in blue is by herself which does not follow the exact day sequences.
Visible crew/equipment: After Phil drives the truck off the cliff, and it explodes in a burst of flames, there is a shot of Andie MacDowell and Chris Elliot staring in shock at the disaster. The two actors are bathed in an orange glow supposedly coming from the flaming wreckage. But in the lens of the TV camera Elliot is holding, there is a noticeable reflection of the lighting equipment used to create the glow effect on the actors.
Continuity mistake: At the end of the movie when Rita reaches over Phil to turn off the alarm clock, we know the clock always goes off at 6:00AM. After turning off the alarm 2 1/2 minutes go by while they are talking and the clock should read 6:02, but when the camera pans to the clock it only reads 6:01.
Other mistake: When Phil is driving the car against the train he ultimately swerves out into a railroad crossing. However when the approaching train is shown from within the car in the last seconds before the two vehicles would collide, there is no crossing to be seen on the remaining track stage between them.