In industrial implementations, CO₂ electrolyzers will likely operate at high temperatures due to heat transfer limitations, but the effects of temperature on surface reactions involved in CO₂ electroreduction remain elusive and heavily based on inference from product analysis. In this study, we used surface-enhanced infrared absorption spectroscopy (SEIRAS) to deconvolute temperature-dependent phenomena affecting the CO population on copper between 20 and 80 °C.