This dataset is part of a research collaboration between Energie und Wasser Potsdam (EWP) and the GFZ Helmholtz Centre for Geosciences. The main objective of this research collaboration was to evaluate the suitability of the subsurface in the Potsdam area for deep geothermal energy. EWP is currently constructing a geothermal power plant using the aquifer of the here exploited Jurassic sandstones. From December 2022 to May 2023, two deep wells were drilled in the center of the city Potsdam, Germany, targeting the Jurassic Aalenian Sandstone at depths between 983 and 1180 m below surface. Hydraulic tests were performed immediately after completion of each well. More than 15,000 m3 of formation water was produced. Geochemical analysis were performed on the produced formation water with the objective of characterizing the fluid properties in terms of geothermal usage, e.g. corrosion and scaling potential. The results of the analysis of physicochemical on-site monitoring and performed on-site tests, inorganics, organics, gas composition, heat capacity and naturally occurring radioactive materials are presented in this data publication.