Ectotherms are particularly sensitive to drought and extreme temperatures, and so may act as bellwethers of climate change. The decline of Hawaiian tree snails in the genus Achatinella has largely been attributed to over-collection, habitat loss, and introduced predators. Currently, most species remain only in captive rearing facilities or predator-free enclosures, following sharp declines and population “blink-outs” observed since 2015. In this study, we developed species distribution models for the ten remaining species in the genus Achatinella under present and future climate scenarios, within the historical range on O‘ahu, as well as areas outside the historical range across the Hawaiian Islands. We found that ~98% of suitable area across the Hawaiian Islands is outside the historical range. Further, end-of-century species distribution models for O‘ahu were consistent with the current distribution of the ten remaining species in the genus Achatinella. Only two species have stable populations outside of predator-free enclosures, suggesting an interaction between threats such as predation and climate change. Our results raise alarms regarding the likely impacts of climate change on wildlife long before the end of the century, and suggest the potential importance of translocations outside the historical range for the persistence of climate-sensitive species.