The purpose of this paper is to propose a numerical model representing the brightness temperature of ten selected sites of the Moon as measured in CERGA. A theoretical approach is proposed in which the temperature is expressed as a function of the local zenith distance of the Sun and a quantity depending upon the local zenith distance of the observer and the difference of their azimuths. The coefficients of this expression depend upon various integrals involving frequency function of the slopes of the lunar surface. The shadows are being qualitatively taken care of by introducing the phase angle ϕ.