A window rod assembly includes two support arm assemblies each including a bracket, a support arm having a first end rigidly connected to the bracket, and a tube rigidly connected to a second end of the support arm; a curtain rod including a first rod section and a second rod section configured in a telescoping arrangement and sized to fit into the tubes of the support arm assemblies; a locking mechanism for securing the relative axial position of the first rod section with respect to the second rod section; and a force adjusting mechanism mounted on at least one of the support arm assemblies and configured to apply an inward force to the curtain rod at a location within the first tube and an outward force to the support arm assemblies to force the brackets into support surfaces of a window opening or window casing.