We present a stress-based indicator for predicting and evaluating the springback behavior of 7075 high-strength aluminum alloy during warm (150 and 250 °C) and hot (490 °C) forming through experiments and numerical simulations. The results indicate that while hot forming yields the minimum springback, the springback angles in warm forming are notably higher and exhibit a decreasing trend as the forming temperature increases. To clarify this behavior, the total absolute stress differential (Stotal) is introduced to quantify the through-thickness stress imbalance. By integrating the numerical model with press equipment parameters including blank holder forces and positions, the Stotal indicator can be used as a computational sensor for monitoring internal stress states. The findings suggest that the reduction in springback at higher temperatures is driven by a marked decrease in the accumulated stress differential, demonstrating a clear positive correlation between these two physical quantities. This work provides a robust mechanical basis for the potential real-time adjustment of forming conditions, facilitating the intelligent quality control of high-strength aluminum alloys at elevated temperatures.