Friction stir welding is a solid-state welding technique that utilizes thermo-mechanical influence of the rotating welding tool on parent material resulting with monolith joint – weld. On the contact of welding tool and parent material, significant stirring and deformation of parent material appears, and during this process mechanical energy is partially transformed into heat. Generated heat affects the temperature of the welding tool and parent material so proposed analytical model for estimation of the amount of generated heat can be verified by temperature: analytically determined heat is used for numerical estimation of the parent material’s temperature and this temperature is compared to the experimentally determined temperature. Numerical solution for analytical estimation of welding plates temperature is estimated using finite difference method – explicit scheme with adaptive grid, considering influence of temperature on material’s conductivity, contact conditions between welding tool and parent material, material flow around welding tool etc.