The aim of the study is to improve the methodology of remote assessment of hydrothermodynamic characteristics of unstudied and poorly studied lakes in northern territories of our country as applied to the task of retrospective and prognostic calculations using mathematical modeling methods. The objects of study are lake regions in the permafrost zone in the Asian part of Russia. Conceptually, the remote sensing methodology is reduced to the following steps. At the first stage, the geographical coordinates of the lake and its area are determined using desktop methods. Further, geostatistical dependences of the average depth of the lake on the water area are plotted, from which the average depth is calculated. The meteorological reanalysis data together with the lake depth are fed into the one-dimensional FLake model and form the basis for retrospective assessment of the lake characteristics. The effects of climate change by the end of the 21st century are estimated based on SSP greenhouse gas emission scenarios. Retrospective and prognostic calculations of hydrothermodynamic characteristics of unstudied water bodies based on the FLake model are performed without its additional verification, since the model used in the practice of weather forecasting by Roshydromet is a priori applicable for the territory of Russia. Hydrothermodynamic simulations were performed for representative points in the lake regions within the permafrost zone. It is shown that the proposed methodology for assessing the abiotic characteristics of unstudied small and medium-sized lakes allows not only to calculate the retrospective dynamics of thermodynamic characteristics of the water column and bottom sediments, but also to assess their possible changes in the future under different climate change scenarios in the Asian part of Russia.