The data set provides a five-year record (2017-2021) of the water stable isotopic composition of snow samples collected every few days at Concordia Station (Dome C), East Antarctica (-75.10°N, 123.35°E, 3233 m a.s.l.). Every sampling day, two snow samples are collected: one at the surface (0 to 1 cm depth) and one at the subsurface (1 to 4 cm depth). The water stable isotopic composition of the samples is measured at the Laboratoire des Sciences du Climat et de l'Environnement (LSCE CNRS Paris-Saclay), France, with a PICARRO L2130-i laser spectrometer. The data is reported with delta-notation (in ‰) with respect to the Vienna Standard Mean Ocean Water (VSMOW).