Summer is typically a season of sunshine, water, and good times, and usually, movies succeed at encapsulating that happy ambiance, however, there are some films that flip summer entirely on its head. Shockingly, these films show the dark, twisted aspect of summer, wherein the heat is oppressive, the air is heavy, and truly anything can happen, including murder. Overall, these thrillers and horror movies use summer to create a terrifying atmosphere that most wouldn't expect from the season, and in this way, these summer films stand out even more for their tragic plots and weighty undertones.