Flow visualization was used to measure hydraulic jump radius on a square plate. Heat transfer between a water jet and a horizontal square surface was investigated experimentally for different jets and square sizes. Effects of flow rates on heat transfer were investigated. The data are represented in terms of Nusselt number as a function of Reynolds and Peclet numbers. A correlation for the Nusselt number in terms of the Peclet number and L/Di was obtained. The proposed correlation predicts the current data of heat transfer very well.