Jack Hall (Dennis Quaid) is a climatologist whose concerns about the dangerously shifting climate are largely ignored by officials at the United Nations. His research proves true when an enormous "superstorm" develops, setting off catastrophic natural disasters around the world. Trying to get to his son, Sam (Jake Gyllenhaal), who is trapped in New York with his friend Laura (Emmy Rossum) and others, Jack and his crew must travel by foot from Philadelphia, braving the elements, to get to Sam before it's too late.