This study used Raman Spectroscopy of Carbonaceous Material (RSCM) to determine the maximum temperatures reached in the external crystalline massif of Western Alps during exhumation related to the Alpine orogeny. Temperatures ranged from 226°C to 389°C from northwest to southeast based on 23 samples. Three cross-sections were realized to better constrain the structure and project the temperature data. A comparison of the Morcles and Mont Joly nappe structures was integrated into a kinematic scenario of massif dynamics. A restoration using the temperature data allows a more precise understanding of the thermal structure between 22-30 million years ago.