In order to address rain attenuation scattering of millimetric waves and microwave in Botswana, we have employed a comparison technique to determine the R0.01 at fourteen diverse locations in Botswana. In addition we have identified two rain climatic zones for Botswana. We note that Mätzler employs Mie Scattering technique to determine the specific attenuation due to rain in Central Europe. Both Mätzler and Olsen use the exponential distribution of N(D) to calculate specific attenuation. In this book we use the Mie scattering approach, but assume several distributions, including the log-normal distribution of N(D) as expounded by Ajayi et al., to determine specific attenuation for tropical and subtropical regions of Africa. The results show that the extinction coefficients depend more strongly on temperature at lower frequencies than at higher frequencies for lognormal distribution. The application of the proposed model is corroborated using practical results from Durban,South Africa. Further, based on attenuation measurements, it is found that the lognormal distribution is suitable for Durban,South Africa.