A unified climate access network provides integrated access to in situ climate data collections and products that are archived among many agencies and sites. Integrated access is directed and managed through a metadata data base, which contains information about the identity and location of observation sites (stations), instruments and observing practices, and data inventories. Metadata integration is accomplished through definition and documentation of station identity and network (data collection) belonging. Core data base tables of information common to all networks support search and select routines, while network-specific data base tables manage information vital to the understanding of specific data collection networks. Associations between networks and climate data variables (elements) provide data quality meaning to climate data products. Historical accuracy of metadata, critical to the interpretation of data, is managed with date accuracy flags. This metadata data base design and management solution is offered as a model for the documentation and integration of metadata for additional climate data collection networks