Estimation of Clearness Index and its Application in Determining Sky Conditions using Three Cities in Ghana as a Case Study

In this work, hourly global radiation and extraterrestrial data for three locations in Ghana, namely Accra, Kumasi, Navrongo, were used to estimate the daily clearness, monthly mean clearness index, monthly-averaged index of study areas. It was observed that average Accra ranged from 0.4505 0.6975 Kumasi Navrongo varied 0.4553 0.6908 0.4529 0.6949, respectively. There no overcast sky year 2018 all areas approximately two-thirds year’s day length experienced clear-sky conditions. Partly cloudy conditions predominant wet season year.