Project: GCOS Earth Heat Inventory - A study under the Global Climate Observing System (GCOS) concerted international effort to update the Earth heat inventory (EHI), and presents an updated international assessment of ocean warming estimates, and new and updated estimates of heat gain in the atmosphere, cryosphere and land over the period from 1960 to present. Summary: The file “GCOS_EHI_1960-2020_Inland_Water_Heat_Content_data.nc” presents an updated estimate of the global heat storage within natural lakes and artificial reservoirs for the period 1960-2020. Several improvements have been implemented in comparison with Vanderkelen et al. (2020): new approach to estimate lake volume, new lake models considered, and an extension of the analysis period. The data are used in von Schuckmann et al. (2022).