Presented here are the results of a numerical study of natural convection heat transfer in a stably stratified, fluid saturated low porosity medium, in which Darcy flow prevails. In this investigation, the boundary layer approximations are discarded and a wide range of ambient thermal stratification levels is considered. The results indicate that the ambient thermal stratification has a significant effect on the flow and temperature fields, and that this effect differs considerably at higher levels of stratification. The flow reversal and temperature defects are significantly smaller in the porous media than in a viscous fluid, due to the stabilization of the flow by the solid matrix. To generalize the result, the Nusselt number data are correlated with the thermal stratification parameter to yield a functional relationship.