There are multiple types of irony at work in “Zero Hour.” Bradbury’s dialogue relies heavily on verbal irony, or a contrast between what is said and what is meant. This occurs in the conversations between the children and their parents: The children discuss the Invasion in cheerful terms, and their parents assume their words to be imaginative nonsense. What the adults mean and what the children mean during the same conversations are completely different, creating disconnect that heightens the theme of Generational Alienation.

Bradbury’s choice of protagonist means that the story also engages in dramatic irony. Dramatic irony exists when the reader or audience is aware of something that the characters in a narrative are not. In “Zero Hour,” Mrs. Morris does not understand what’s going on, but the reader is cued by Mink and the other children’s words and behavior, and thus able to identify that something bad—i.e., the invasion—is going to happen.