For wireless communication systems, the channel is free space or atmosphere. An atmosphere consists of many particulates such as gases, rain, fog, snow, hail, temperature, etc. Due to all these parameters the signal strength will be attenuated. Especially at microwave frequencies, more amount of energy of microwaves is lost or attenuated by these parameters. At low atmospheric pressures, the attenuation and phase dispersion on the wideband signals will be more and results the signal distortion. Due to this signal distortion, more bit errors will occur and causes the presence of inter symbol interference (ISI) in the received signal. In this paper, we have obtained the attenuation due to various atmospheric parameters such as water vapor, oxygen, clouds, hydrostatic.