Deforestation, urbanization, agriculture, and other human development practices have substantially modified and fragmented natural surfaces. Anthropogenic land use change and the resulting landscape alterations have important implications to local, regional, and global climate patterns by changing the energy balance on Earth's surface. As a result of increasing population in the last fifty years, the Southwest shows significant decreases in forests and pastures and increases in urban areas and special uses areas (roads, airports, industry, national defense installations). To quantify the anthropogenic land use changes on regional climate signal in the Southwestern US we perform dynamical downscaling with the Weather Research and Forecasting (WRF) model initialized with the National Centers for Environmental Prediction (NCEP) reanalysis data and the Max Planck Institute European Center/Hamburg Model version 5 (ECHAM5) General Circulation Model for representative current and future periods under different land cover scenarios. We systematically evaluate the downscaled datasets with respect to common baseline datasets, and then apply statistical bias correction and uncertainty analysis to establish objective confidence intervals. We perform detailed analysis of the bias data for each land use scenario to isolate the effect of land use change on the hydrometeorological variables.