The climate of Mississippi has been considered to be ideally suited for the production of soybeans. Many studies have shown the influence of weather on crops, but none that specifically attempt to pinpoint which aspects of weather have an impact on the Mississippi soybean crop. The purpose of this study was to determine what affect weather has on the phenological period length and yield of Mississippi soybeans. Data on bean phenological periods and yield used in this research were recorded as a part of soybean variety testing conducted at Delta Research and Extension Center in Stoneville, Mississippi from 1976-2000. The major statistical procedure used in this study was Pearson?s Correlation Analysis that was used to determine any significant relationships between soybeans and weather. This study found that cooler temperatures and more moist conditions positively influence yield in Mississippi soybeans, while energy is more important in determining period lengths than water.