Diary of a Wimpy Kid: The Meltdown

On a hot day in January, Greg worries about climate change and how it will impact his life in the future. When he forgets about a social studies assignment, his mother punishes him by not allowing him to watch television or play video games. Greg is unable to play outside due to a rivalry between groups on his street: those who live on the straight Lower Surrey Street or the slanted Upper Surrey Street. The day after, his family unsuccessfully searches for their pet pig, which they acquired during the events of The Long Haul, who had escaped from obedience school.

Greg is frustrated at school when his classmates are unsanitary, and struggles with the cold weather. While walking to school, Greg is stopped by the Safety Patrol, an authoritative organization of only female students. The students begin rioting at the school when they fear that they will be snowed in overnight, and are dismissed early.

Greg and his friend Rowley take the bus of the rival Whirley Street, and are mistakenly blamed for having thrown a snowball at the bus driver. The two are kicked off the bus and dropped off near the woods, where they accidentally wander into the camp of the Mingo Kids, a savage group who live in the woods. However, Greg and Rowley are saved when they come across Greg's father.

The next morning, Greg meets with Rowley and builds a snow fort, indirectly starting a snowball fight among the Upper Surrey Street kids. They agree to team up after being ambushed by the Lower Surrey Street residents, and build a single gigantic fort, enjoying early success but slowly being demoralized as the Lower Surrey Street kids begin besieging the wall. A Lower Surrey Street spy lures many Upper Surrey Street defenders away from the fort, allowing the Lower Surrey Street kids to destroy it, but the long-resentful school Safety Patrol begin to attack the various Surrey Street kids. The Whirley Street kids get involved, but they as well as the Surrey Street and Safety Patrol kids band together against the attacking Mingo Kids. Tired of the violence, Greg and Rowley attempt to hide in the remains of the snow fort, but when a delayed snowplow arrives and drives through the remains of the fight, everyone agrees to stop fighting. Days later, the weather begins to clear up. Greg is glad that he survived the snowball fight.