This report represents The RAND Corporations portion of a study conducted by the U.S. Weather Bureau to determine the impact of research in the atmospheric sciences on the social and economic activities of the nation. This report is devoted largely to a discussion of the benefit to be derived from improved weather information. The thesis is advanced that weather information has value principally because it leads many people and organizations to make the decisions that counter the deleterious effects of weather. This hypothesis is then used both to explicate the difficulties of evaluating atmospheric research in economic terms and to suggest techniques for improving weather information and estimating the value of weather information thus improved.