A method is presented for predicting the long-term statistics for rain depolarization in the case of spatially nonuniform rain, based on previous calculations for the uniform case. These calculations apply to any type of linear polarization. Assuming a lognormal form for the point rain rate statistics and using the idea of space-averaged rain rate, an approximate normal form is deduced for the probability density function of the cross-polarization isolation (XPI) or discrimination (XPD) in decibels. The parameters of this normal density are shown to be dependent on the parameters of the radio link and the rain rate distributions. These include the probabilities of rainfall along that particular path, the median and standard deviation of the point rainfall rate, the spatial correlation coefficient of the rainfall rate, radio frequency, path length, and type of polarization.