Airborne observations of sea-ice plus snow thickness were made between June and August 2013 as part of the Antarctic Winter Ecosystem and Climate Study (AWECS) during the Polarstern cruise PS81 (ANT-XXIX/6). The data record consists of 6 helicopter surveys over sea ice in the Weddell Sea, a rare case of winter airborne sea ice surveys in the southern hemisphere. For each flight, the geolocated sea-ice plus snow thickness data from an airborne EM sensor is provided with a point spacing of approximately 5 meters. The trajectory data contains only data records with valid retrievals. Larger gaps in the trajectories arise at high-altitude calibrations of the EM sensor. Each thickness value represents the average thickness within an area of approximately 40 meters, thus representing a smoothed representation of the true total thickness. The data is routinely used for quality control of satellite remote sensing data and for sea-ice process studies that include the sea-ice thickness distribution.