Dan is a twelve-year-old boy living in Grand Island, Nebraska. He views himself as an active person who prefers doing things over thinking about them. He loves riding his racing bicycle and considers himself an excellent cyclist. At home, he struggles with feelings of jealousy and resentment toward his new baby brother, creating friction with his parents.

Arthur is Dan's closest friend. He has dark skin, wavy black hair, and a stockier build than Dan. Known at school as "the Original Gazer," Arthur is highly observant, thoughtful, and enjoys reading books. He frequently analyzes situations and recently made an Indigenous American bull-roarer toy in a summer crafts class.

Stacey is Arthur's fourteen-year-old sister. She has long black hair and dimples, and she is well aware that Dan has a crush on her. Stacey spends most of her free time with her friend Evelyn. She possesses a natural warmth and nurturing instinct, often looking out for the younger members of her community.

Linda is Dan's mother. Before the birth of her youngest son, she worked at a beauty salon and maintained a cheerful demeanor. Currently, she feels exhausted and overwhelmed by the constant demands of caring for a fussy infant. She sews clothing in her spare time and tries to manage the rising tension between her husband and older son.

John is Dan's father, a mechanic who enjoys working on engines. He spends his free time meticulously restoring a 1953 Corvette in the family garage. He also helps his own parents out on their farm. He expects Dan to pitch in around the house and expresses vocal frustration when Dan acts selfishly regarding chores.

Goldie is Linda Hatch's younger sister. She is a divorced woman who teaches dance at the Riverside Dance Studio and runs summer crafts programs to help support herself. Dan considers her a bit flaky, but she possesses a warm, affectionate nature and openly sympathizes with the boys' daily frustrations.

Belle Smiley is an elderly woman who lives alone in Dan's neighborhood. She is very small in stature and walks with a distinctive side-to-side sway. She acts kindly toward the local teenagers and takes immense pride in maintaining her home, particularly her newly upgraded aluminum storm door.

Officer Kelly is a local policeman in Grand Island. He tries to use humor to put frightened civilians at ease, joking that he has a standard cop name that is easy to remember. He faces immense pressure attempting to manage the chaos as extreme weather descends on the town.

Mrs. Minetti is a female officer and matron who oversees the women's section at the local police headquarters. She has brown hair and friendly eyes. She acts with a distinct maternal instinct toward the young people seeking shelter at the station, providing them with basic comfort and snacks.

Ryan is Dan's baby brother. Because he is teething, he cries frequently and requires constant attention from his parents. His presence has completely altered the dynamic of the Hatch household, making him an unwitting source of tension for his older brother.

Ronnie Vae is Arthur and Stacey's ten-year-old sister. She is one of several girls in the large Darlington family and often tags along with her older siblings during their summer outings.

Mr. Darlington is the patriarch of the large Darlington family. He works two jobs to support his wife and many children, meaning he is only home on Sundays. He works at the local armory.

Mrs. Darlington is Arthur and Stacey's mother. She manages a chaotic household containing seven children while her husband works. Dan notes that she is kind to everyone. She enjoys reading romance novels in her spare moments.