The ventilation climate information system (VCIS) allows users to assess risks to values of air quality and visibility from historical patterns of ventilation conditions. It is available through an interactive, Internet map server that allows maps of ventilation potential to be overlain with sensitive receptors, terrain features, or political boundaries. The ventilation index data apply to local, regional, or national scales, for use by local, state, tribal, and federal managers of smoke or other pollutants. Maps and graphs of historical ventilation conditions can be included in fire- or smoke-management plans, used to illustrate concerns in public meetings, and overlain with other values at risk. The data can be used to help develop plans for avoiding smoke impacts and optimizing the use of prescribed fire at specific places or certain times of year. Spatial patterns of risks to air quality and visibility are illustrated in maps of monthly averaged values. Frequency statistics at selected points show temporal dimension of risk. Values at risk can be assessed for specific airsheds and compared over time or with other airsheds.