The monthly averaged daily global solar radiation is calculated using daily data of global solar radiation obtained by measurements at six weather stations at different locations in Oman over a period of 6 years. The clearness index for a typical day (at midday) of each month is then estimated for each location. Also, the hour ly values of different components of solar radiation (direct, diffuse and global) over these six stations are estimated for a typical clay of each month by applying empirical models and using the standard meteorological data for each station.