AbstractThis manuscript investigates the impact of land‐surface heterogeneity on atmospheric processes by comparing 92 large‐eddy simulation cases over the Southern Great Plains, leveraging high‐resolution spatially heterogeneous and homogeneous land‐surface fields. Utilizing the HydroBlocks land‐surface model for detailed surface data and the Weather Research and Forecasting model for atmospheric simulations, this study emphasizes the significant role land‐surface details play in atmospheric dynamics, particularly in cloud formation and boundary‐layer development. The analysis focuses on the comparison of turbulent kinetic energy and liquid water path between heterogeneous and homogeneous surface conditions, revealing a strong correlation between surface heterogeneity and enhanced atmospheric activity. Furthermore, the study underscores that the most influential land‐surface characteristics on the atmosphere are encapsulated within the largest spatial scales, suggesting a potential simplification for incorporating sub‐grid scale land‐surface features into global models. The findings advocate for a more formal coupling between the sub‐grid land and atmosphere in Earth system models to improve the accuracy of weather and climate predictions, particularly for processes such as cloud formation and boundary‐layer dynamics that are sensitive to surface conditions. This work lays foundational insights for future parameterization schemes in global models, highlighting the importance of land‐surface details on atmospheric modeling.