The paper presents a real time weather routing solution based on an Evolutionary Algorithm (EA). The objectives to be minimized are the mean total risk and fuel cost, where the route of a ship is optimized while taking into consideration the time-varying sea and weather conditions and there is also a constraint on the total passage time of the route. Safety is also taken into account by applying restrictions following the guidelines of the International Maritime Organization (IMO). The proposed EA implementation is tested on real life instances and compared with an exact algorithm.