The film begins in year 2009, when there is a huge explosion on the surface of the sun. We then see Adrian Helmsley (Chiwetel Ejiofor), an American scientist, traveling to a copper mine in India to meet his friend, who discovered that Earth's temperature is increasing rapidly. He returns to Washington D.C. and submits a report to his supervisor, who immediately takes him to the president. In 2010, we see the President of the United States tell other heads of state the situation (the world is ending) and we also see billionaires all over the world buying plane tickets for untold sums of money. In 2011 the original of The Mona Lisa in the Louvre is replaced with a decoy, and is sealed away for unknown reasons.

The story jumps ahead to 2012. Jackson Curtis (John Cusack), a divorced father who works as a limousine driver and writer, and his ex-wife, Kate Curtis (Amanda Peet), and children, Noah (Liam
James) and Lily (Morgan Lily), who live with Kate's new boyfriend, Gordon (Thomas McCarthy). Jackson takes his children on a camping trip to Yellowstone, where he meets Charlie Frost, who hosts a radio segment that addresses the Mayans' prediction. Charlie mentions a map of where special ships are, but Jackson assumes he is a rambling drunk and leaves him. Kate and Gordon and in a supermarket buying groceries when the floor begins to crack and the supermarket is split in half. Jackson gets a call that he has to return from camping with the kids. Jackson arrives at the house and drops the kids off, and takes his limo to a job. He goes to the house of Russian billionaire Yuri Karpov. Jackson takes Yuri, his children and his girlfriend to the airport. The children make cruel comments to Jackson, and as they board the plane, they mention they have tickets to board the ships and Jackson doesn't. This leads Jackson to believe Charlie's story, and he rents a plane. Jackson hurries to Kate's house and picks up her, the kids, and Gordon as the house collapses and a massive earthquake begins. They drive through L.A while it is being destroyed and arrive just in time at the airport.

When they get to Santa Monica Airport, the pilot that Jackson hires is killed by a falling structure. Kate mentions that Gordon knows how to fly (Gordon protest's, he has only had a few lessons) so they tell him to fly the plane out of L.A. From the sky, we see L.A sinking into the Pacific Ocean. Jackson announces they have to get to Yellowstone to get the map from Charlie. They fly there and Jackson goes looking for Charlie. He finds his R.V and takes it out looking for Charlie, and he finds him at the top of a hill waiting for the impact. Charlie tells Jackson where the map is and he rushes back to the R.V as a massive explosion goes off, hurtling rocks in every direction. Jackson gets to the plane and they take off for China.

The group lands in Las Vegas and they meet Yuri. Yuri's plane is damaged, but he and Sasha, Yuri's pilot, find a cargo plane that carries automobiles. Las Vegas is destroyed by earthquakes and ravaged by the impeding volcanic ash cloud of Yellowstone. Yuri has 2 children and his girlfriend with him.

While in the air, the group learns that the plane does not have enough fuel to reach China: they've passed Honolulu, Hawaii, which has been inundated in lava. As they're about to ditch the plane they discover that they are no longer above the ocean: the Earth's crust has shifted thousands of miles and they are heading towards the Himalayas. During a crash landing on a glacier they manage to escape from the plane safely by using one of the luxury vehicles in cargo as a raft. The group ditches the car and a helicopter lands, they ask for tickets and Yuri shows his three tickets. He goes on the helicopters with his 2 children and leaves his girlfriend and the group behind.

The group eventually finds their way to the ships with the help of some locals and is smuggled aboard with the help of a Buddhist monk and a construction worker. Gordon dies as they board. Tsunamis begin to engulf the Indian peninsula, and a giant wave eventually reaches the ships, which turn out to be arks constructed to save the heads of state, hand-picked individuals chosen to repopulate the earth and the rich elite, who could afford to buy tickets. A massive flood is heading towards the ship, and due to a wire left by Jackson in the ships gate, the gate isn't able to close, and the engines aren't able to start. Jackson manages to get the gates closed just in time, and the ships cruise off. A title appears that says Day 27 Month 01 Year 01. The group is living on the ark, and Jackson and Kate seem to have gotten back together. The captain of the ship learns that Africa was able to miss catastrophe and is safe to venture too. The ship heads for Africa, and a view from space shows all continents have moved together and are in the shape of Africa.