Diurnal observations of the variation of the radar backscattering coefficient &sgr;0 and microwave apparent radiometric temperature Tap with snow wetness mv are presented. The results show that &sgr;0 decreases and Tap increases with mv and that the magnitude of the sensitivity to mv increases with microwave frequency for both active and passive microwave parameters. Moreover, while the sensitivity of &sgr;0 to snow wetness varitations increases with angle of incidence, the sensitivity of Tap to snow wetness is approximately angle of incidence independent.