Silicon nanowires (Si NWs) terminated with hydrogen atoms exhibit higher activation energy under ambient conditions than equivalent planar Si(100). The kinetics of sub-oxide formation in hydrogen-terminated Si NWs derived from the complementary XPS surface analysis attribute this difference to the Si-Si backbond and Si-H bond propagation which controls the process at lower temperatures (T < 200 °C). At high temperatures (T≥ 200 °C), the activation energy was similar due to self-retarded oxidation. This finding offers the understanding of early-stage oxide growth that affects the conductance of the near-gap channels leading towards more efficient Si NW electronic devices.