This study aims to estimate the impact caused by certain weather conditions on the workload of the ATCO who operate in the TMA-SP. In order to do so, eight specific days were simulated in the TAAM simulator, seven of which contained different bad weather conditions for aviation. The results show an increase in the controllers' workload, which affects important sectors where the movement of flights is already considered heavy. Critical weather conditions and times are identified and can serve as the basis for strategic planning of safety and operational efficiency in the context of air traffic management. It is important that the one responsible for air traffic flow management actions consider them, as this can help minimize the impacts caused by delays on air­lines’ direct and indirect costs as well as on air transport users. Academically, it is necessary to carry out research on the automation of operational actions with the pur­pose of reducing the controllers’ workload.