The IOP4H2O campaign took place at the AWIPEV station in Ny-Ålesund from 20. January – 10. March 2025. Researchers from the University of Cologne and the University of Leipzig from the (AC)³ E05 project intensively investigated humidity and temperature profiles for detailed sublimation processes using various instruments. In addition to the routine measurements at the AWIPEV station (https://www.awipev.eu/), the scientists installed a W-, Ka- and G-band cloud radar, as well as a laser precipitation monitor and snow-particle-counter. Furthermore, the measurements were accompanied by an additional 78 radiosonde ascents. The range of weather conditions was very wide with rain and +4°C, storms with winds up to 30 m/s, snow, cirrus as well as EarthCARE and HALO overflights. The evaluation of the data obtained is therefore very promising.