Aeration is an effective method for reducing deterioration of stored grain. A finite volume method was used to simulate temperature variations and distributions in stored paddy rice in a warehouse-type facility during cooling aeration. A CFD (computational fluid dynamics) software package (Fluent 14.0) was used to develop a model to solve coupled nonlinear heat, mass, and momentum transfer equations. An experiment was conducted in a large-scale (commercial) warehouse storage facility to measure temperature distributions in the stored paddy rice to validate the CFD model. The stored grain was aerated for 30 h, and temperature was measured at five depths within the grain bulk and at 24 locations for each depth. The simulated temperatures were in good agreement with the measured values, with relative differences less than 6.3%. The CFD model was shown to be effective in assessing the uniformity of temperature distribution in the grain bulk during aeration and the performance of the aeration system.