What temperature does the title of 'Fahrenheit 451' refer to?

The title 'Fahrenheit 451' refers to the temperature at which paper catches fire. Ray Bradbury used the figure as the symbolic threshold at which books, and the ideas they contain, can be destroyed by the society's firemen.

The novel was published in 1953 and follows Guy Montag, a fireman whose job is to burn books rather than extinguish fires. In Montag's world, books are treated as dangerous because they encourage independent thought, disagreement, and uncomfortable reflection. His growing curiosity about what books contain turns him against the system he serves.

The temperature is conventionally given as 451 degrees Fahrenheit, or about 233 degrees Celsius. Bradbury said the number came from a conversation with a fire-department official about the temperature at which paper ignites. The title is therefore not the melting point of paper, the combustion point of wood, or the temperature at which ink burns.

The number also works as a memorable warning: censorship does not merely remove information from libraries; it attempts to erase the habit of thinking. The novel's fire imagery is deliberately double-edged, since fire can destroy books but can also provide warmth and community.