Current and future risks posed by wildfires are key elements in decisions about management of those fires. Carrying evaluations of that risk more than a few days into the future requires stochastic approaches that depend on the climatology of environmental conditions that favor or deter wildfire growth. Tools like the Fire Spread Probability (FSPro) simulator, and the Rare Event Risk Assessment Process (RERAP) before it, apply climatology in this way. This analysis identifies key environmental factors using spatial and temporal distributions of Moderate Resolution Imaging Spectroradiometer (MODIS) fire detections. The Fine Fuel Moisture Code (FFMC) and Buildup Index (BUI) from the Canadian Forest Fire Danger Rating System (CFFDRS) define the critical climatology of conditions favorable for significant fire growth in Alaska's Boreal Interior. These conditions are used to inform the stochastic analyses and demonstrate the potential for effective and useful results.