The National Meteorological Archive of Germany holds the physical i.e. paper meteorological records created by the DWD and its predecessors from its foundation in 1848. This data covers Germany and includes terrestrial, marine and upper air. These contain all main meteorological elements and encompass autographic records and tabulated data in various forms. Note: data from marine vessels is held at Deutsche Seewarte in Hamburg (Germany). The Deutsche Seewarte in Hamburg houses a collection overseas stations (from outside Germany) for the period 1870-1945 (mainly 1900-1914)
Projects have started digitizing these paper documents.
Kaspar, F., Tinz, B., Mächel, H., Gates, L. 2015: Data rescue of national and international meteorological observations at Deutscher Wetterdienst. Adv. Sci. Res. 12, 57-61, doi:10.5194/asr-12-57-2015 (http://www.adv-sci-res.net/12/57/2015/)