People love to talk about the weather, usually to complain. One thing no one complains about is Indian summer: this occurs when it's fall, and the brisk, cooler fall weather is interrupted by summer-like weather. In Indian summer — which could last a couple days or even a couple weeks — the temperatures shoot up. When there's Indian summer, people rush to play frisbee, have picnics, and walk the dog. Indian summer is also called Saint Martin's summer.