Computing the flow field under natural convection in a cavity becomes particularly challenging at low Prandtl number (Pr) fluids such as in liquid metals. In this study, our objective is to examine the problem by employing the transition SST model for Prandtl number Pr ∈ [0.001, 0.1] and Rayleigh number, Ra ∈ [104, 107]. The mean flow field is visualized through streamlines, isotherms, nondimensional velocity and temperature profiles and contours of intermittency(γ)×production of turbulent kinetic energy(κ). The flow field transit to oscillatory nature at a critical Ra which is found to increase with increasing Ra and reducing Pr. Transition SST model however is able to capture the flow field in all three flow regimes successfully. The average Nusselt numbers (Nu) are tabulated within the range of controlling parameters as a function of both Ra and Pr. This could be beneficial for engineering applications involving the use of liquid metals having low Pr.