The turbulent heat transfer characteristics in a stagnation region were investigated experimentally for an axisymmetric submerged air jet impinging normal to a heated flat plate. The temperature distribution on the heated flat surface was measured by a thermochromic liquid crystal (TLC) with digital image processing technique. To get precise heat transfer data inside the stagnation region, a fully developed straight pipe nozzle was used in this study. The stagnation Nusselt number was correlated for the jet Reynolds number and the nozzle-to-plate spacing as Nu theta alpha Re 0.565(L/D)0.0384. For the nozzle-to-plate spacing of L/D=2, the stagnation Nusselt number varies according to Nu theta alpha Re 0.050 and the local heat transfer rates exhibit two maxima. The primary and secondary maxima are attributed to the accelerated radial flow and the transition from a laminar to a turbulent boundary layer, respectively. For larger nozzle-to-plate spacings (L/D<6), the local heat transfer decreases monotonically with radial distance. The Reynolds number dependence is enhanced as L/D increases (Nu theta alpha Re0.58 for L/D=6 and Nu theta alpha Re0.65 for L/D=10). This results from the increase of the centerline turbulent intensity of approaching jet due to strong momentum exchange with ambient fluids.