The dataset includes water vapour isotopic composition measured in Antarctica during the East Antarctic International Ice Sheet Traverse (EAIIST) between November 2019 and February 2020. This file includes data from the Concordia interior station, and is part of a long term monitoring of the vapour isotopic composition. The data was collected to study the variations of isotopic composition with the local climatic parameters in extremely remote and dry regions of Antarctica in order to understand better the isotopic paleothermometer. The data was collected thanks to three Picarro L2130i instruments during the traverse in the framework of Casado et al, [manuscript under review].