Due to the ability of clay vessels to store and retain water below ambient temperature, it has become a basic commodity for water storage among the rural dwellers in the Sub-Sahara region and as an alternative to other cooling/refrigerating system. It therefore, becomes necessary to study and determine how effective and efficient porous clay pot serves as evaporating coolers. Evaporative cooling of water in six different porous clay vessels was studied under varying ambient conditions. In this study, water was stored in six porous clay vessels of different sizes and volumes. The weight, relative humidity, and ambient temperatures of water content in the porous clay vessels were measured bihourly from 12 noon to 8 pm for a period of 7 days. The result of the study revealed that the mass loss is affected by several factors such as ambient temperature, the surface area of the vessel, porosity and thickness of the vessel. From this study, pots with small water holding capacity (Pots D and E) experienced the fastest rate of evaporation. The relative humidity was based on the condition of the environment. This study concludes that energy demand can be minimized by applying evaporative cooling concept in households, offices, and industries. Thus, this paper provides an insight towards ways of conserving energy demand for cooling as there is no requirement of electricity to run the system. Hence, extensive usage of these sorts of cooling systems helps in providing greener environment.