Here we provide 3 conductivity, temperature and depth (CTD) measurements, and a temperature and depth (TD) time series for Lake Motzfeldt. The CTD measurements were taken with an RBR concerto in August 2025. The time series was measured with an RBR Duet3 between August 2024 and August 2025. The time series was corrected for atmospheric pressure variations with a Van Essen Diver placed close to the lake (baro.csv). All coordinates of CTD and TD measurements are provided in coordinates.txt. The .rsk files can be read with the pyRSKtools Python package. CTD01_230582_20250731_1537.rsk CTD02_230582_20250803_1648.rsk CTD03_230582_20250801_1657.rsk TD_230400_20250801_1925.rsk baro.csv coordinates.txt Reference: Vacek, F., Nick, F. M., Benn, D., Zwarts, M. P. A., Immerzeel, W., and van de Wal, R. S. W.: Contrasting dynamics of lake- and marine-terminating glaciers under same climatic conditions, EGUsphere [preprint], https://doi.org/10.5194/egusphere-2025-5733, 2025.