This study describes the modelling of the thermal behaviour of aquacultural ponds through nodal discretisation and the use of correlation formulae for exchanges at the water-air interface, The direct resolution of the resulting system was effected by an interconnected numerical method. The experiments carried out on a test pond provided the database necessary for refining the model. The satisfying comparison of experimental and simulated responses for the pond water justify the choice of theoretical approach. A data-processing tool was developed on a PC computer to determine the water temperature of a parallelepiped pond of variable geometry and composition, subjected to different demands and with or without thermal protection covering.