The aim of this paper is to establish the detailed numerical results of the laminar natural-convection flow along a vertical wavy plate. A typical sinusoidal surface is used to elucidate the heat-transport phenomenon for the gas having variable thermophysical properties. The present work treats the viscosity, thermal conductivity, and density of the gas as a function of temperature. The numerical solutions are obtained after converting the governing equations into a suitable coordinate system. The results are interpreted for the parameters that emerge from the temperature-dependent physical properties of the gases and transverse curvature of the surface. To ensure the accuracy of the results, the present numerical solutions are compared with some special cases and are found in good agreement. The key observation from the present analysis is that the amplitude of the wavy-surface parameter contributes in the reduction of the heat transfer rate. It is also shown that the momentum and the thermal boundary-layer thickness increase substantially for the nonuniform properties of the gas.