What is the Impact of Rain on RF Signal Propagation?

As we go higher up in frequency the intensity of precipitation or rain starts to have a significant effect on atmospheric attenuation. In addition to the the signal being absorbed by the atmosphere at particular frequencies, raindrops are roughly the same size as the radio wavelengths at higher frequencies which result in the scattering of RF signals which is a major cause of attenuation.

Most cellular communication i.e 2G/3G/4G use frequencies below 5 GHz which are not impacted that much by rain, however backhaul communication between base station and the ISP/network provider use higher frequencies (between 20 and 80 GHz). These higher frequencies are impacted by rain and thus can impact cellular communication.