When hard times hit Swallow Falls, its townspeople can only afford to eat sardines. Flint Lockwood, a failed inventor, thinks he has the answer to the town's crisis. He builds a machine that converts water into food, and becomes a local hero when tasty treats fall from the sky like rain. But when the machine spins out of control and threatens to bury the whole world under giant mounds of food, Flint finds he may have bitten off more than he can chew.
His genius finally recognized by his idol Chester V, inventor Flint Lockwood (Bill Hader) gets to join Chester's company, where he can work full-time on technologies to help mankind. However, Flint soon discovers that his most-famous machine, which turns water into food, is still operating but now creates animal/vegetable hybrids. With the fate of humanity in Flint's hands, he and his friends set out to save the world from tacodiles, shrimpanzees and other deliciously dangerous creatures.