This paper depicts the stability charts of rectangular plates clamped to an infinite, rigid baffle in uniform subsonic flow. The correlations among the critical flow speeds and the plate aspect ratio, plate thickness/length ratio, and plate/fluid density ratio are exhibited. Results show that when the flow speed exceeds a critical value, the plate may vibrate around an equilibrium position other than its undeformed one. When the flow speed exceeds all the critical values, the plate may be locally unstable at all equilibrium positions. In particular, it may jump from one equilibrium position to another in a random fashion. These local instabilities are controlled by structural nonlinearities. Without the inclusion of structural nonlinearities, the plate may have only one equilibrium position, namely, its undeformed one. The amplitude of plate vibration would then grow unboundedly when the flow speed exceeds the critical value, known as absolute instability. With the inclusion of structural nonlinearities, the plate may have more than one equilibrium position when the flow speed exceeds the critical values. Under this condition, plate vibration may seem chaotic, the overall amplitude of flexural vibration is nevertheless bounded.