The region around the tip of the Antarctic Peninsula is one of the fastest warming regions of the world, a situation that will lead to widespread changes in permafrost state, local hydrological cycles and biological activity. Further, it is located in the path of the southern westerly winds, one of the poorest-understood components of the global climatic system. The sedimentary archives in the lakes from the ice-free regions on this region host a yet untapped wealth of information on the past changes and links between the regional climatic, hydrologic and biological systems. Especially important are the stable isotope compositions of these sediments, but to understand how they record these changes, an in-depth knowledge of their links to present-day conditions is required. We present here the first study of the stable isotope composition of the surface waters in the ice-free southern peninsulas of King George Island, Antarctica. Our results suggest that a clear separation of the various water bodies (permafrost, snow, meltwater, lakes) based on the stable isotope composition of the water is possible, allowing for future studies aiming to understand (changing) feeding behavior of terrestrial fauna. Further, water in lakes on a W-E transect have distinct stable isotope composition, leading to the possibility of studying the past changes in the strength and dynamics of the westerly winds in the region.