Atmospheric conditions during drying have been modeled in a climatic chamber to evaluate the effect of desiccation in soil layers. Different environmental variables such as relative humidity, wind velocity, radiation, and temperature have been measured. The climatic chamber was designed and calibrated to simulate properly each environmental variable and the heat transfer mechanisms during desiccation process. A potential evaporation tests was performed measuring the weight of water and actual evaporation tests were performed in a soil layer of Speswhite clay, in these tests, potential and actual evaporation rate were determined. This paper presents the evolution of the environmental variables and the soil properties such as soil temperature, water content, and suction during the evaporation process. As a result, a comparison between potential and actual evaporation rate indicates the large effect of suction on the actual evaporation rate.