- Copernicus’ Upper Air (moving platform), Marine Metadata and Land Surface Metadata Datasebase: https://data-rescue.copernicus-climate.eu/
- NOAA’s HOMR (Historical Observing Metadata Repository) , a station history database accessed at https://www.ncdc.noaa.gov/homr/. This includes GHCN-D, NWS-Coop, Global Land Surface Databank, Integrated Global Radiosonde Archive and other keyed digital datasets.
- NOAAs FORTS (Military Forts and Voluntary Observers base), an Image Inventory of over 4000 United States stations from about 1740-1892 accesed at: https://mrcc.illinois.edu/FORTS/inventory1.jsp