Climate change threatens to increase extinction rates due to rapidly warming global temperatures. Species distribution models (SDMs) are critical to predicting the potential threat of a warming world by estimating an organism’s capacity to remain active in their habitat given their physiological requirements and local climatic conditions. However, SDMs often ignore the capacity of animals to acclimate by reversibly adjusting physiological traits in response climatic conditions. By being susceptible to rapid dehydration, amphibians might increase skin resistance to water loss (ri) in order to maximize the amount of time available for activity. We tested the capacity of an abundant terrestrial salamander (Plethodon metcalfi) to acclimate ri in response to natural changes in climatic conditions that occur with elevation and seasons. We measured ri of salamanders using a flow-through system capable of precise control over temperature and humidity. The results demonstrate that salamanders consistently increase ri in response to warm temperatures and high VPDs. We then used a mechanistic SDM to understand how acclimation of ri can influence activity time. Under a warming climate, the SDM predicts that average nightly activity time will be reduced by 60% by 2100 without acclimation. However, incorporating acclimation of ri increases average nightly activity time by 26% relative to predictions without acclimation. These results underscore the potential for acclimation of physiological traits to improve predictions on the effects of climate change by incorporating important biological processes.