From Introduction: For the purposes of these rules, weather consists of three basic ingredients: temperature, wind, and precipitation. Each of these categories is presented as a hazard. To create a weather condition, just pick a hazard for each and combine their effects. The hazards are designed so that they do not conflict. You can match any temperature effect with any wind effect, and the two function independently of each other. In some cases, you can select more than one hazard for a type. Precipitation covers fog in addition to hail and rain. In addition, you could create a storm that delivers both rain and hail. The sample storms given below serve as a guide to illustrate how you can combine these effects. Common sense serves as your best guide in putting together storms and effects. In addition, the section on long-term weather provides ideas and guidelines for creating sensible weather patterns for an area. Note that in some cases the weather traits draw on material presented in the core rules. While the basic rules remain the same, they have been adapted to fit into the design and classification scheme presented here.