Ray Bradbury's story "All Summer in a Day" is set on Venus. This location is extremely important to the story because of the nature of the weather on Venus. In the story, it rains every day on Venus. In fact, due to astronomical and climate conditions, the sun only comes out once every seven years.
Many of the children in the story, who have been born on Venus, have never seen the sun. Margot, however, was born on Earth and has dim memories of the sun from that time. This makes her different from the other children and a target for their abuse.
The climax of the story hinges on the moment the sun finally comes out. Margot is locked in a closet right before the sun is supposed to come out, where she remains, forgotten, while the other children play in the sunshine. The ending of the story is ambiguous; when the children let Margot out, it is not clear how Margot will respond.