Microelectromechanical systems (MEMS) with high out-of-plane stiffness are less susceptible to adhesion than more compliant structures, but reliable operation of sliding contacts still requires surfaces that exhibit adequate friction and wear performance after long periods of storage. Alkylsilane monolayers are popular surface treatments for silicon devices, and there has been some research to understand the performance of monolayers as a function of environment. However, there have been limited investigations of the tribological behavior of these surface treatments after exposure to harsh environments. There is a need to quantitatively determine the effects of storage environments on the performance of MEMS interfaces, rather than verifying device functionality alone. To this end, surface micromachined (SMM) structures that contain isolated tribological contacts have been used to investigate interface performance of alkylsilane monolayers after storage in inert environments, and after exposure to a variety of thermal and radiation environments. Results show that both octadecyltrichlorosilane (ODTS) and perfluorodecyltrichlorosilane (PFTS) exhibit little change in hydrophobicity or friction after Co-60 radiation exposures at a total dose of up to 500 krad. However, exposure to temperature cycles consistent with packaging technologies, in the presence of low levels of water vapor, produces degradation of hydrophobicity and increase in static friction for ODTS films while producing no significant degradation in PFTS films.