From January 2022 to May 2023, temperature and salinity (only until March 2023) data were logged with a SEABIRD SBE 37-SMP MicroCAT CT in 2-minutes intervals at GEOMAR (Kiel, Germany) pier at 54°19'48.8N, 10°08'59.6E. The sensor system is mounted to a floating platform to ensure a continuous depth of 1 m at any time. After cleaning and other re-boots of the sensor package, temperature and salinity data tend to deviate from true values. Hence, 60 minutes of data after any re-boot (after sensor servicing with re-deployment, data download or power failure) were deleted. Due to massive fouling the conductivity sensor caused false salinity data during the last two months of this measurement period which were, hence, also deleted from the data set.