A weather-based financial index is based at least in part on weather. The index may take into account any of a variety of weather factors, such as temperature, precipitation, humidity, number of sunny or overcast days in a period of time, number of freeze days in a period of time, etc. Weather factor value(s) are combined with one or more financial components to provide the weather-based financial index. The index may be traded on an exchange, such as the New York Mercantile Exchange (NYMEX). The value of the index may be calculated based on any period or on any geography (or combination of geographies). Historical values of the index or component(s) thereof may be used to predict future values of the index. Values of the index may provide insight into the direction of a component of the index, a market or industry corresponding to the component, or the index itself.