Isolating the effects of the type and concentration of the dopant in lightly doped regions in the reaction between hydrogen-terminated silicon surface and atmospheric impurities in air is very difficult. However, changes in the surface recombination sites can be analyzed accurately through recombination lifetime measurements performed using the microwave photoconductive decay method. Thus, we investigated variations in the effective recombination lifetime in hydrogen-terminated silicon surfaces over time in air for different dopant types and concentrations. For both p-type and n-type silicon wafers, surface recombination velocity, S, increased with decreasing resistivity, namely, increasing dopant concentration. The time-dependent variations of the S for the p-type wafers decreased, and those for the n-type wafers increased with decreasing resistivity. Thus, it was shown that the time-dependent variation of the S depends on the type and concentration of the dopant used.