We produced new hydrogen and carbon isotope records from Lake Towuti and Lake Matano in Sulawesi, Indonesia using long-chain n-alkanes. We compared these new records to existing records from the same lakes and compiled available marine runoff, salinity, leaf wax hydrogen isotope (d2Hwax), and leaf wax carbon isotope (d13Cwax) records in the IPWP. During the last deglaciation, marine runoff and salinity proxies reveal that precipitation amount began to increase dramatically between ~12.3 ka and the end of the Younger Dryas. A principal component analysis of precipitation isotope records indicates a shift from more 2H-enriched to 2H-depleted waxes at ~12.3 ka as sea level rise inundates most of the Sunda and Sahul shelves, coincident with runoff and salinity proxies, suggesting precipitation isotopes respond strongly to rainfall amount in this region. Over 70% of IPWP d13Cwax records show a transition from more to less 13C-enriched waxes beginning about 20.5 ka, prior to the reconstructed increases in precipitation.