This paper presents the development and assessment of a numerical method for simulated site calibration. The wind flow over complex terrain is predicted with a small length scale resolution. The flow field is resolved with the Reynolds averaged Navier–Stokes equations, complemented by the turbulence model, with special treatment of the ground boundary to account for very large roughness lengths such as forest. The computational model is solved using FLUENT . A complex site, Riviere au Renard, located in Gaspesie, QC, Canada, has been selected and data have been collected from five met masts installed on this site. An experimental data analysis has been undertaken with emphasis on uncertainty evaluation. Three sets of results are presented. First, the numerical method is validated over flat terrain by comparing the simulation results with Monin–Obukhov similarity theory. Second, the assessment of the numerical method over complex terrain is done by comparing the wind velocity profiles at three of the met masts for three different wind orientations. Finally, traditional and numerical site calibrations for Riviere au Renard are presented for two wind directions. The numerical results are within the experimental data uncertainty.