The paper analyzes the dynamics of the main climatic indicators in order to reveal the role of regional and local factors in the current changes in the water content of the Svitiaz Lake (NW Ukraine). The current state of study of the water balance of the lake and the factors that form it are estimated. The main trends for changes in the levels and regime of surface water, groundwater and artesian water in the territory of the Shatsk National Nature Park are identified. Quantitative data characterizing long-term and modern changes in water levels in the lake are presented. Shallowing of 2019 is characterized (the lowest water level over the last 50 years, reduction of the water mirror area by 8%). Based on statistical mathematical and cartographic analysis of climatic data provided by 17 meteorological stations in the region the dynamics of average annual, monthly and seasonal precipitation, evaporation and their spatial distribution were estimated. A significant increase in evaporation during the warm period of the year over the last decades (2000-2018) has been revealed. Changes in the amount and mode of precipitation over 2 long-term periods are estimated. The peculiarities of the dynamics of the main meteorological indicators in 2019 (average monthly and average annual air temperatures, relative humidity, precipitation amounts) were separately analyzed. Values of humidity coefficients and hydrothermal coefficients were calculated. The parts of the region with the lowest values of these indicators, including the catchment area of Lake Svityaz, are outlined and visualized on the map. The significant role of evaporation growth was confirmed given the consistent increase in air temperatures over the last 20 years. Given the Svityaz station data it is also calculated the correlation coefficients of water levels in the lake with the same indicators for the period since 1970. During the period of 2000-2018, a significant increase in the dependence of water levels on the hydrothermal coefficient of Selyaninov was established, which may indicate a decrease in the ecological stability of the lake and its increasing vulnerability to climate change.