Lowered sea levels during the last glacial interval exposed the Bering Land Bridge, connecting eastern Asia with western Alaska. This land mass provided a biogeographic route for ancient plants, animals and people, plants and animals to move across between Asia and the Americas. However, there is very limited environmental and climatic information from the central Bering Land Bridge. Here we provide a suite of biomarker data as proxies for past environmental conditions, including temperature, covering the last ~18,500 years from a sediment core from St. Paul island in the south-central Bering Land Bridge. Our data indicate that there were considerable changes in both temperature and precipitation the period after 18.5 ka and prior to sea level covered covering the surrounding region (~11 ka) there were considerable changes in both temperature and precipitation. These changes could have provided important impetus and context for people and animals to move from the Bering Land Bridge well before the region became entirely submerged by rising sea-levels after the last ice age beneath the ocean.