Ventilation is the process of exchanging air in a closed space to provide good indoor air quality. Computational Fluid Dynamics (CFD) has become one of the most important and reliable tools to assess natural ventilation. This paper presents the effect of wind direction on temperature and velocity inside a building with outlet windows at leeward wall and side wall. The CFD simulation was performed using Reynolds-Average Navier-Stoke (RANS) approach with k-ε model. The selection of standard k-ε model is due to suitability of this model to perform the wind speed profile and temperature profile inside the building. Validation of cross-ventilation is performed based on earlier Particular Image Velocimetry (PIV) measurements and shows very minimal discrepancy between CFD and PIV result. The result of velocity and temperature shows that the wind speed and temperature inside a building strongly depends on the incident winds angle and outlet opening of the building.