Abstract In this study, we use the one-dimensional hydrodynamic model DYRESM to simulate the Lake Kinneret thermal structure over a period of 45 months. We focus on the application of a new version of the one-dimensional hydrodynamic model to Lake Kinneret and simulation of the physical processes. DYRESM is calibration-free process-based model that simulates the vertical distribution of temperature and salinity in lakes and reservoirs. The current model is a complete rewrite of the original DYRESM code. Each algorithm was simplified to the essential minimum physical description yielding a more robust and faster model. The new model underwent validation with a high quality dataset from Lake Kinneret. The model simulation reproduced the temperature of the surface layer of the water column to within less than 1 °C. Results of a sensitivity analysis indicated that the surface and bottom water temperatures were most sensitive to changes in long-wave radiation. We conclude from the results that the simplified version of DYRESM accurately simulated the physical processes in the lake although planned inclusion of a benthic boundary-layer routine will improve the model’s ability to simulate the bottom temperatures.