A simile is a comparison of two UNLIKE objects or ideas using the words "like" or "as" to connect them. Scout, as the narrator of the story, uses similes, but she doesn't use them in conversation except at the end of the story.
1. When Miss Maudie's house catches fire, Scout relates how the smoke looked coming off the houses.
"Smoke was rolling off our house and Miss Rachel's house like fog off a riverbank." (pg 70)
Smoke is being compared to fog off a riverbank in this sentence.
2.When Jem tells Calpurnia about the mad dog, Scout describes how he told her.
"Jem gulped like a goldfish, hunched his shoulders, and twisted his torso." (pg 93)
Jem is being compared to a goldfish ---- two UNLIKE things.
3. When Atticus finds out about Jem cutting Mrs. Dubose's camelia bushes, Scout tells how he came into the house.
"....Atticus was at the hat rack in the hall----- and we heard him call 'Jem!'. His voice was like the winter wind." (pg 103)
Atticus's voice is being compared to the winter wind, cold and uncomfortable.
4. When Jem and Scout are attacked by the man as they make their way home Halloween night, she describes the man,
"His stomach was soft,but his arms were like steel." (pg 262)
The attacker's arms are being compared to the strength of steel.
5. When Scout is told that Mr. Ewell fell on his knife, she knew that Boo had killed Mr. Ewell. She tells Atticus that she understands. Atticus asks her what she understands. She replies,
"Well, it'd be sort of like shootin' a mockingbird, wouldn't it?" (pg 276)
She is comparing blaming Boo Radley for Mr. Ewell's death to killing a mockingbird. You do not kill a mockingbird because all mockingbirds do is make music for us to enjoy.
The page numbers are for my edition of the book. They should be in close proximity to those numbers.