The existing system for sensing, recording, and reporting climatic conditions has been developed mainly in response to demands of specific clients. Weather conditions provided for airline navigation, agricultural production management, and severe storm tracking, are three examples. Thus, the system for producing, storing, and disseminating climate data has strong historical linkages to the demands of major clients and the sensing and recording technologies available at the time of implementation. Locations of first order stations at airports, the cooperator system, frequency of reporting, and the levels in the atmosphere at which data are recorded all can be viewed as having a user based history.