Factual error: Air descending cannot cause temperatures to reach a point where things freeze as fast as they do in the film. Firstly, the temperature of the upper troposphere is only -60° Fahrenheit. Secondly, air will warm as it descends no matter how fast it's descending, and the warming process will always prevent the air from getting cold enough to freeze things as fast as in in the movie.
Revealing mistake: In the scene where Dennis Quaid jumps over the ice crevasse to the other side, note the position of his ice axe, which is strapped to the right side of his hip. When he jumps back over with the metal tubes in his hands, he balances a little, then falls. We see his gloved hands disappear as he falls into the crevasse. The next shot shows he is holding onto the ice axe, which is embedded into the ice with his left hand. In reality he would not be able to unhook the ice axe so quickly and then put it in his left hand and thrust it into the ice. Remember what gravity does.keiko
Revealing mistake: During the tornado scene there is a part where you see lots of cars on the highway flying and crashing and if you look carefully at the second car falling it doesn't touch the ground, yet it manages to cause sparks and dents.
Continuity mistake: When the students are looking around the library for books to burn, it cuts to a girl and man standing on the balcony beside a book cart. When the guy reaches across to grab a book and says, "We can't burn this one..." he is holding the book with both hands, but in the following shot his left hand is on the book and the other hand is on the cart. (01:11:35)The-Immortal
Factual error: When we see a TV report saying how England is affected by the storm we see a shot of a street with hanging yellow traffic lights. England doesn't have yellow traffic lights, we have black ones. It's obviously footage of a storm in the United States.
Continuity mistake: In the scene where Sam smashes the vending machine in the library, you see him first take out about three items from it, and then in the next shot you see him holding two items, but when he throws them onto the table there are about a dozen packets of sweets and crisps. (01:11:25)
Continuity mistake: Just after Terry looks at the boys on the screen with Simon, in the overhead shot of Manhattan traffic, the homeless guy in the middle of the traffic is walking towards a black car with a police car beside it. But in the following closeup he has passed the cop car and is now at the bumper of the black car. (Zoom in is required). (00:19:00)The-Immortal
Continuity mistake: The older scientist reaches down to grab Jack with his right hand. In a closeup, Jack grabs the right hand and the same scientist catches him with the left hand as well. In the next shot from above, only his left hand is down, but as he pulls Jack up both hands are on him. (00:05:40)Phoenix
Continuity mistake: Near the start, when it cuts to a street in Japan, a large hailstone hits the policeman's car. When it hits, the wipers just brush it away and keep working, but in the following shot when the policeman looks back at his vehicle, the hailstone is still there and the wipers are no longer working. (00:10:45)The-Immortal
Other mistake: In the scene where the first storm appears, you see little windmills spin and trees affected by this wind. However, the hair of the old man walking out of his house (in the same shot) is undisturbed. (00:23:30)
Factual error: When the students arrive in New York, you can see the luggage tag on Laura's bag. It lists JFK below DCA. This means the bag would have flown from somewhere to John F. Kennedy airport in New York, and then connected onto another flight going to Reagan National in Washington DC. Since New York is their final destination, JFK should have been the top airport code, even if they had connected through somewhere else.
Continuity mistake: When all the people are in the library sheltering from the cold, in the overhead shot of the guard (the one who told the homeless guy he can't enter the library with a dog), he is in front of Laura and then walks to his right with clothing/blankets in his hand, but in the next shot he is behind Laura and the black cop. (00:58:40)The-Immortal