Most mandatory metadata are provided by the network providers, but consistent climate, land cover, and soil characteristics are provided from external data sources. If available, data providers can optionally share their own characterizations of land cover, soil, and quality control flags with the ISMN. These are stored in addition to the mandatory variables, so that the mandatory variables remain consistent between networks.

Fetching metadata information (land-cover, soil information and climate classification) from the ISMN database is not as trivial due to the complex structure of the ISMN database, resulting from efficient data integration. As a consequence of this, a python module was created at TU Wien several years ago which reads and plots data from downloaded ISMN files and offers a much more user-friendly way of extracting metadata information for needed stations. This module is freely available on GitHub: Additionally, information about static variables (e.g., land cover classification) are also included in the downloaded zip-folder as one csv-file per station-separated subfolder. Furthermore, downloaded stm-files include labels concerning the ISMN's and the data provider's quality flags.