<p>Climate change exerts a profound influence on animals in natural ecosystems, causing significant shifts in the suitable habitats of many species. These changes are occurring at different rates and scales depending on the species. Species with temperature-dependent sex determination (TSD) are particularly sensitive to changes in incubation temperature during the critical period of sex determination, rendering them more vulnerable to climate change. Here, we applied species distribution models to project suitable habitats and potential sex ratios for three congeneric gecko species (<i>Gekko swinhonis</i>, <i>G. japonicus</i>, and <i>G. hokouensi</i>) under both current and future climatic conditions. Our modeling results indicate that the decline in habitat suitability will be more pronounced for <i>G. swinhonis</i> compared to the other two lower-latitude species. Furthermore, projections indicate that the future degree of sex ratio bias in <i>G. swinhonis</i> will be intermediate between those of <i>G. japonicus</i> and <i>G. hokouensis</i>. Our model predictions were made by using relatively moderate monthly mean temperatures and taking no account for the maternal effects associated with nest selection and hormonal regulation, but they still imply that the three gecko species are facing serious threats due to their pattern of sex determination. Our study is the first to demonstrate that higher-latitude TSD species may face more severe ecological consequences under future climate change scenarios, underscoring the necessity of incorporating population sex ratio dynamics into assessments of climate-change impacts on TSD species along latitude gradients.</p>