This dataset provides the weighted averaged salinity derived from two Delft3D Flexible Mesh (FM) model simulations representing the low discharge (fall 2021) and high discharge (spring 2021) seasons. The weights for each model were determined using the probability density function of the Atchafalaya River discharge. Each model was run for 31 days, excluding a 1-day warm-up period from the analysis. Salinity is calculated by applying a weighted average to the salinity values at each grid cell in the final time step of each simulation. The data are provided in netCDF format.