Soil heat flow and the resulting soil temperature distributions have ecological consequences related to plant growth, metabolic processes of soil-dwelling microorganisms, and survival strategies of soil-dwelling animals. The study of soil heat flow requires that soil temperature be obtained. In some instances, actual measurement of soil temperature profiles and heat flux can be used. In other instances, actual measurements may not be available due to lack of equipment, inaccessibility of the site, or inconvenience. In these instances a model is used to predict soil temperatures from more readily attainable environmental variables. This module focuses on the modeling approach.