This module addresses the local and regional climatological considerations and presents tools and methodologies that can be used to assess whether atmospheric conditions can foster fog or low stratus development. Knowing your local climatology and assessing whether it supports favorable conditions for fog or low stratus development is an important step in the forecast process. A number of physical conditions that determine fog or stratus development are largely dictated by climatological restraints, as well as the synoptic pattern. This module is part of the Distance Learning Course 1: Forecasting Fog and Low Stratus.