Climate Data Record (CDR) of Arctic sea ice age spanning the period from 1991 to 2024. The dataset is based on a novel Lagrangian advection scheme applied to a triangular mesh, which conserves sea ice age fractions and reduces numerical diffusion compared to the previous Eulerian approach. The sea ice age is derived from satellite observations of sea ice concentration and drift, representing fractional age classes per grid cell. The record captures the spatial and temporal evolution of first- to sixth-year ice, including uncertainty estimates that account for both sea ice concentration and drift uncertainties.