Hence, in this work, we compare RNA and DNA hydration reorientation dynamics using short model double-stranded sequences adopting the typical helical conformations (A-form for RNA, B-form for DNA), and obtain for the first time a picture of the hydration dynamics at a single-site resolution. Combining our simulations with an analytic model to describe the mechanism of water reorientation and the impact of a biomolecular interface, we then provide an unprecedented molecular level rationalization of the main differences between ds-DNA and ds-RNA hydration dynamics.