Firn core OH-11 was retrieved from Plateau Laclavere, a small ice cap on the northernmost end of the Antarctic Peninsula, at about 1130 m above sea level (a.s.l.). It was drilled in January 2015 to a depth of 20.44 m. The core was obtained using a portable solar-powered and electrically operated ice-core drill (Backpack Drill; icedrill.ch AG). Subsamples for stable water isotope analysis were obtained at 5 cm resolution. Stable water isotope measurements of OH-11 were conducted at the Stable Isotope Laboratory of the Universidad Nacional Andrés Bello (UNAB) in Viña del Mar, Chile, in autumn 2015 with an off-axis integrated cavity output spectrometer (TLWIA 45EP; Los Gatos Research). The core has not been dated yet.