This paper presents a comprehensive approach to forecasting hydro–meteorological changes in a marine area, i.e., in large bodies of water, from open water to coastal zones. First, hydro–meteorological factors, their interactions, and their implications for marine ecosystems are described. In addition, an analysis is outlined specifically for the Baltic Sea area. Next, the procedure for forecasting expected changes in major hydro–meteorological parameters in the sea is presented and a series of steps is accurately described. An extensive prognosis is provided for the southern Baltic Sea region using historical data obtained from the Polish National Institute of Water Management and Meteorology. The procedure is applied for seven measurement points which were assigned to four sub-areas for examining trends in wind regimes and wave height patterns using the authors’ own written software and statistical methods for data analysis. The model was validated within the southern Baltic Sea region. This paper also highlights the significance of forecasting for human beings, the environment, and critical infrastructure by proposing adaptive strategies and integrated coastal zone management in mitigating risks and enhancing resilience. Finally, future directions for research are proposed.