Populations should adapt to the climate at their respective localities. Here, we examined differences in thermal biology between two populations of Podarcis hispanica lizards from areas with different climates. Lizards from the cold, northern mountains attained lower field body temperatures than lizards form the warm, southern plains. However, the larger body size and darker coloration of northern lizards resulted in slower cooling rates, which may increase efficiency of thermoregulation. Northern populations selected higher temperatures in a thermal gradient, possibly as an adaptation to heat up before conditions changed, as their mountain environment is unpredictable. Finally, lizards from both populations had similar temperature-dependent locomotor performance curves, although southern lizards were relatively faster considering their smaller body size. We suggest that environmental differences may lead to differences in morphology and locally adapted thermal biology in lizards that might allow maximizing thermoregulation in each local climatic conditions.