Navigation systems, methods, and programs output on an output device information on a set normal travel route when a guidance route for providing guidance to a user is not set. The systems, methods, and programs set a reference route satisfying a predetermined first setting condition as the normal travel route, and when the user travels along a temporary route that shares a start point and an end point with the reference route and is different from the reference route, specify a temporary travel factor that is a factor in which the user travels along the temporary route. The systems, methods, and programs set a second setting condition that varies depending on a content of the specified temporary travel factor, and change the normal travel route from the reference route to the temporary route, based on the second setting condition.