The permittivity and attenuation of prepared samples of wet snow are measured and curves presented showing the dependence of these quantities on snow wetness and frequency. Equations are given that express the experimentally determined relation between attenuation per unit length and volume‐percent wetness at any frequency between 4 and 12 GHz. Additional equations are given for the calculation of permittivity from the snow density, attenuation per unit length, and frequency. Water retention characteristics of snow are described. Some applications of the techniques, such as runoff forecasting from mountain snowpacks, are proposed.