In Ray Bradbury's Fahrenheit 451, what temperature does the title identify?

In Ray Bradbury's Fahrenheit 451, the title identifies 451 degrees Fahrenheit.

The number refers to the temperature at which the novel says book paper catches fire and burns. It appears in the story’s opening line, which describes Montag taking pleasure in burning things. Firemen in Bradbury’s society do not extinguish fires; they destroy books and the homes that contain them.

The temperature is a literary symbol as much as a technical label. It represents censorship, the suppression of difficult ideas, and the replacement of sustained reading with fast entertainment. Bradbury later acknowledged that the exact ignition temperature of paper can vary with paper type, moisture, and other conditions.

Fahrenheit 451 was published in 1953. The protagonist, Guy Montag, begins as a fireman who accepts the system before questioning it. The novel is often described as a censorship dystopia, although Bradbury also emphasized the effects of mass media and declining attention.