This paper reports the water temperature structure and associated coastal processes in the NE part of the Black Sea. In situ temperature was measured in the water area of the Utrish Nature Reserve. The thermistor chain was moored in 2020 and included 6–10 temperature sensors with an accuracy of ±0.025 °C and time step of one minute. The seasonal variations in the water temperature, upwelling events, internal waves and diurnal...