The setting provides the location for the action of the novel it can also provide historical and cultural context for the characters.
The setting is in the future, as are most Science Fiction novels, the setting sets the backdrop for the action, the world that Montag inhabits has evolved beyond the need for education and learning. In an effort to achieve sameness, to sanitize the population of any possible conflicts among the people, all the people are the same.
The setting in this book brings us into the world as it is, the world that Montag lives in with his wife, Mildred, the Fire house, his job as a fireman, the book burnings. It also illustrates a world that is mostly gone in the presence of the character Clarisse McClellan, whose family clings to the old ways, so this gives the reader perspective on the history of the society in which Montag lives.
The setting can also symbolize the emotional state in which the characters live, in this novel, Mildred's emotional state is illustrated by her need for her fourth wall, the giant television screens, of which she has three in order to view her "family" as she calls them. These people on the television show are more important to her than her husband.
Then there is the setting which includes Faber and the other members of the resistance movement, they are an example of the possible future, where books might become valuable again.
Faber and the book people are a small group who might be the only survivors after the war, that is about to erupt, takes place, so they are part of the future.
The setting is in the future approxamitely around our time... it does not specify where the story takes place
fahrenheit 451takes place Approximately around that 24th century and does not have an exact setting