A route search system includes an electronic control unit configured to perform: acquiring estimated weather information, the estimated weather information being information about weather that is estimated in a region where a candidate of a first route from a departure place to a destination place exists; acquiring experienced weather information, the experienced weather information being information about weather that a user has experienced in past; an searching the first route by preferentially selecting a first road over a second road, and outputting information about the first route, the first road being a road in a first region where the estimated weather information coincides with the experienced weather information, the second road being a road in a second region where the estimated weather information does not coincide with the experienced weather information.