The study investigates the effect of anisotropic thermal expansion on the oxygen evolution reaction (OER) performance of Sr$_2$IrO$_4$ catalysts. By heating, compressive strains are induced in the IrO$_6$ octahedra, downshifting the $d$-band center and optimizing the binding strength between OER intermediates and the Ir active species. This results in a nonlinear Arrhenius relationship for OER kinetics, indicating that the thermal strain effectively tunes the electronic states of Sr$_2$IrO$_4$. The findings demonstrate that thermal stimulation can be a simple and effective method to enhance OER performance beyond traditional thermal diffusion effects.The study investigates the effect of anisotropic thermal expansion on the oxygen evolution reaction (OER) performance of Sr$_2$IrO$_4$ catalysts. By heating, compressive strains are induced in the IrO$_6$ octahedra, downshifting the $d$-band center and optimizing the binding strength between OER intermediates and the Ir active species. This results in a nonlinear Arrhenius relationship for OER kinetics, indicating that the thermal strain effectively tunes the electronic states of Sr$_2$IrO$_4$. The findings demonstrate that thermal stimulation can be a simple and effective method to enhance OER performance beyond traditional thermal diffusion effects.