This dataset provides the weighted average hydroperiod derived from two Delft3D FM model simulations representing the low discharge (fall 2021) and high discharge (spring 2021) seasons. Each model was run for 31 days, excluding a 1-day warm-up period from the analysis. The weights for each model were derived from the long-term probability density function (PDF) of the Atchafalaya River discharge. Hydroperiod, which quantifies the frequency of inundation at each model grid cell, is computed by analyzing the water level time series and identifying periods when the water depth does not exceed the model-defined wet/dry threshold of 5 cm.