For more than 60 years, Radar data have been used to estimate rainfall rate. But the paradigm is shifting and its applications are being exploited in fields of cloud detection. This paper also takes a step in doing so. Firstly, Radar reflectivity (ZHH) is compared to the occurrence of rainfall and a particular relation between the two is observed. Results are presented to show that rainfall events occur when ZHH is greater than 20 dBZ. Thus it is a matter of interest and also the purpose of this study, to point out the causes behind ZHH less than 20 dBZ, if not rain. Secondly, ZHH is compared to ground based cloud images and it is found that cloud can be the possible reason for lower values of reflectivity. Hence, this paper exploits the usefulness of weather Radar in fields of cloud detection.