This study examines the influence of outdoor phenomena together with temperature changes around an isolated building. Considering different wind velocities, temperature differences and building heights, several numerical CFD simulations were performed to investigate the effect of the temperature on the recirculation zones, for various characteristics of the ambient flow field. In the first part, the temperature effects between undisturbed air and building surface were analyzed together with their impact on the flow field. In the second part it was also taken into consideration the influence of the solar radiation. Finally the study was completed by evaluating how different building geometries can affect the previous scenarios. The results show the importance of the temperature variation for the ventilation around the building and how it modifies, in a significant way, the fluid dynamics close to the building envelope. The correlations found allow to make a proper estimation of the extent of the recirculation regions near the building. (C) 2016 Elsevier B.V. All rights reserved.