By in-situ x-ray reflectivity measurements we observed an ordered layer near the (001) surface of a CuAu single crystal well above the bulk transition temperature. An Au-rich uppermost layer induces a temperature dependent oscillating order profile perpendicular to the surface, which is accompanied by strong lattice relaxations consistent with the tetragonal near surface structure and the cubic disordered bulk. The Parrat recursion formalism was used to model the Fresnel refiectivities resolving the electron density distributions on an atomic scale.