The present invention generally discloses a weatherproof flush adapter plate assembly. In one embodiment, the adapter plate assembly includes a plate. The plate includes a front side, a back side, an outer edge, at least one inner edge, at least one mounting member for receiving a back box and at least one mounting member for receiving a notification appliance. The adapter plate assembly also includes a first gasket coupled to the front side of the plate and a second gasket coupled to the back side of the plate.