The main objective of this study was to collect and evaluate climatic and soil data pertaining to Oklahoma for the climatic model (EICM) in the mechanistic-empirical design guide for pavements. The EICM climatic input files were updated and extended over a large area covering Oklahoma climatic conditions. Large cluster of raw climate and soil moisture data were obtained from the Oklahoma Mesonet for evaluation and use in creating the necessary input parameters for the climatic model. Historical climatic data were also employed for classifying climatic regions in Oklahoma using cluster analysis. Thornthwaite Moisture Index (TMI) contour maps were created using the climatic data and ArcGIS software. A comprehensive validation study was also undertaken in comparing the moisture migration processes in the EICM and commercially available software using the climatic and soil data in Oklahoma.