Temperature and heating-induced temperature difference profiles were measured through the atmosphere, sea ice, and ocean using a SIMBA-type sea ice mass balance buoy equipped with a several meter long thermistor chain. The present dataset was recorded by SIMBA 2015T20 (original name Awi_62) installed on drifting sea ice in the Central Arctic Ocean during the expedition Polarstern PS94 (ARK29/3,TransArcII) in 2015. Data is available between 2015-09-25 09:00:00 and 2016-03-22 18:03:00. The thermistor chain was Variable 5 m long and included 240 sensors with a regular spacing of 2 cm. The resulting time series includes the evolution of temperature and temperature differences at 30 s and 120 s during a heating cycle of 120 s as a function of location, depth and time. The sampling intervals were usually between hourly and daily, but were most frequently configured to 6 hours for temperature, and 24 hours for temperature differences. In addition to temperatures and geographic location were measured. The present dataset was processed as follows: obvious inconsistencies (missing values) and unrealistic values of GPS position have been removed. This instrument was deployed as part of the project projects FRontiers in Arctic marine Monitoring (FRAM) and Sea Ice Physics @ AWI (AWI_SeaIce).