Evie is a sardonic teenager who serves as the primary narrator of the story. She possesses a keen awareness of the climate crisis and holds the older generation directly accountable for the planet's decline. Despite her cynical exterior, she acts as a highly capable surrogate mother to her younger brother. She feels entirely alienated from the adults around her, choosing instead to bond with her peers over their shared frustration.

Jack is Evie's nine-year-old brother and the moral center of the youth group. After receiving a book of Bible stories, he reads them without traditional religious context, viewing them instead as allegories for nature and science. He acts with open-hearted compassion, focusing his energy entirely on rescuing wild animals from the impending storms. He exhibits a bravery that contrasts sharply with the adults' apathy.

Burl is a modest, altruistic groundskeeper who quickly takes on a leadership role for the stranded children. Unlike the well-educated but helpless parents, Burl possesses practical survival skills and a level-headed demeanor. He acts as a reliable guide, directing the youths to higher ground and establishing contact with emergency resources.

The parents are a clique of well-heeled professionals spending their summer vacation in a continuous haze of alcohol and drugs. They represent the older generation's willful negligence regarding the climate crisis. In emergencies, they exhibit complete ineptitude. They rely entirely on escapism rather than taking practical action to ensure their children's safety.

'The governor' is the ruthless leader of a scruffy, heavily armed militia that takes advantage of the post-storm lawlessness. He postures with grandiose arrogance, keeping his hand tucked into his shirt like Napoleon. He relies entirely on intimidation, theft, and extreme physical violence to secure resources for his desperate followers.

Terry is a squat, bespectacled teenager who acts as the resident intellectual of the friend group. He employs an ornate vocabulary to elevate himself above others during conversations. His highly articulate nature makes him the unofficial spokesperson for the youths when they are forced to negotiate with the negligent adults or outside threats.

Jen is one of the teenage girls in Evie's primary friend circle. She acts as a caretaker for her younger, Deaf brother, Shel. During the beach trip, she briefly develops an infatuation with the older yacht boys but remains fiercely loyal to her core group of friends as the environmental situation deteriorates.

Shel is Jen's eleven-year-old brother, who is Deaf. He closely shadows Jack throughout the summer, sharing Jack's deep devotion to nature. Together, the two boys form a dedicated team focused on rescuing local wildlife from the rising floodwaters and storing them safely in the treehouses.

David is the most technologically savvy teenager in the group. He possesses a strong sense of climate justice that sometimes manifests as impulsive retaliation against the wealthy elite. He carries significant guilt over the potential consequences of his hacking actions.

Kay is David's eleven-year-old twin sister. She shares a highly volatile and occasionally violent relationship with her twin, leading to physical altercations that the older teenagers must break up. Her behavior reflects the growing chaos of the environment around them.

Amy is David's eleven-year-old twin sister. She is frequently at odds with Kay, suffering injuries during their intense physical fights. When the violent storm hits the great house, Amy goes missing, causing immense stress for the surviving youths.

Sukey is one of the teenage girls in Evie's group. She is heavily focused on social dynamics and exhibits a cynical streak regarding religious texts. She holds deep resentment toward her mother, actively avoiding her even as the weather crisis worsens.

Sukey's mother is one of the adult guests from the rented mansion. Unlike the other parents who remain immobilized by the disaster, she actively seeks out the children. She tracks down her daughter while in the late stages of a hidden pregnancy, a condition the teens initially misinterpret as weight gain.

At seventeen, Alycia is the oldest teenager in the rented mansion group. She frequently uses her age and appearance to manipulate adults and bypass restrictions. She leverages her father's own illicit behavior to avoid punishment, showcasing a cynical understanding of adult hypocrisy.

Alycia's father is part of the adult vacation group. He tries to enforce parental authority but is completely undermined by his own extramarital affairs. His lack of moral standing makes him entirely powerless to control his rebellious older daughter.

James is the self-assured alpha male of a group of extremely wealthy teenagers vacationing on the yacht 'Cobra'. He boasts about his family's luxurious survival compounds and generators. He cynically maintains a polite facade with his tycoon parents solely to ensure his place in their high-tech climate bunkers.

Juicy is a fourteen-year-old boy in Evie's group, nicknamed for his overactive salivary glands. He possesses a highly immature sense of humor and frequently targets other teenagers with bigoted insults. He relies heavily on his family's significant wealth for security.

Rafe is one of the older boys in Evie's group and is openly proud of his identity as a gay teenager. He exhibits a strong sense of physical capability, stepping up to disarm hostile individuals during crises. He holds deep contempt for the entitled yacht teenagers and maintains a fiercely protective stance over his younger friends.

Low, short for Lorenzo, is an adopted teenager from Kazakhstan who frequently boasts about descending from Genghis Khan. He acts as a grounded presence in the group, taking on caretaking duties for the younger children while others attend parties. He remains highly critical of extreme wealth and entitlement.

Val is a quiet, agile tomboy in the teenager group. She rarely speaks but is highly observant, using her exceptional climbing skills to traverse the environment. The adults frequently exploit her physical agility, dispatching her to handle dangerous tasks like repairing the roof during a lightning storm.

Dee is a teenager in Evie's group who struggles with loyalty between her friends and her parents. When the group establishes a sustainable system away from the adults, Dee finds the separation difficult and eventually chooses to maintain a closer connection to the older generation, despite their flaws.

Luca is one of Burl's friends, part of a group of altruistic volunteers known as 'trail angels'. He possesses emergency medical training and immediately puts his skills to use treating injuries and coordinating life-saving procedures. He acts as a calming, highly competent presence during extreme crises.

Darla is an altruistic volunteer and friend of Burl. She takes a philosophical approach to the ongoing climate crisis, finding deep meaning in natural phenomena like the aurora borealis. She shares her love of poetry with the children, establishing an impromptu school to keep their minds engaged.

Mattie is a biologist and member of the 'trail angels' volunteer group. He applies his scientific knowledge to help the children manage the rescued animals, advising them on the most humane courses of action. He bravely endures physical torment from hostile intruders to protect the farm's food supply.

John is an altruistic volunteer and friend of Burl. He works alongside his fellow trail angels to help the displaced children build a sustainable life at the farm. He teaches the youths history, acting as an impromptu educator during the crisis.

The farm owner is an immensely wealthy, unseen presence for much of the novel, operating from TriBeCa while laying down strict rules for her rural property. When she finally appears, she commands a private tactical team. She displays maternal kindness toward the young children but enforces her property laws with absolute finality.

Evie's mother is a feminist theory professor attending the summer reunion. Despite her highly educated background, she exhibits a complete inability to engage with the immediate physical crisis. She prioritizes stockpiling alcohol over preparing the house for the incoming hurricane, firmly ignoring her daughter's practical concerns.

Evie's father is a fashionable, upscale artist known for incorporating left-wing politics into his work. Despite his intellectual posturing, he actively avoids discussing the climate crisis or taking any personal responsibility for it. His ongoing apathy causes a deep, irreversible rift between him and his children.

David's mother is one of the adult vacationers staying at the rented mansion. Like the others, she participates in the hedonistic behavior of the group. However, she eventually shows a rare moment of selflessness by warning her children to stay away from the mansion when a dangerous, mosquito-borne fever spreads among the adults.

Red is a red-haired teen associated with the armed looters. During the invasion of the farm, he attempts to force Evie to reveal hidden supplies but falls into a trapping pit, breaking his leg. He is later given a surprising second chance by the property's owner.