Abstract
Dynamic changes in stream water temperature are caused by thermal energy exchange at the interface between the water and the atmosphere, and between the water and the streambed. This heat flux is the result of physical processes which are stimulated by external drivers that control water temperature both in temporal and spatial scales. For streams, the most characteristic are diurnal fluctuations of temperature. For the purposes of this paper, electronic data loggers were used which allowed a presentation of the diurnal cycles of water temperature in a small lowland river. The measurements confirmed that meteorological conditions have a significant impact on the diurnal dynamics of stream temperature.