The weather of a world or region may be calm, or it may be extreme. It may be predictable, or it may be wild. It may be typical, full of clear days interspersed with a few rainstorms, or it may be extreme, typified by massive firestorms. The weather of your world helps define it in far reaching ways, from the types of creatures that may inhabit it, to how civilization has adapted to life there. The weather you choose for your world could be the difference between an umbrella and a bunker.