ABSTRACT: Monthly average daily global solar radiation data are essential in the design and study of solar energy conversion devices. In this regard, different empirical models based on Angstrom-Prescott model were selected to estimate the monthly average daily global solar radiation (H), on a horizontal surface for Sokoto State using sunshine duration, relative humidity and temperature. The hourly solar radiation data measured at Sultan Abubakar III International Airport station during the period (2005–2015) was used to calculate the monthly mean values of H using selected models. The selected models were compared on the basis of the statistical error tests such as the mean bias error MBE, the mean percentage error MPE, the root mean square error RMSE, Nash–Sutcliffe equation NSE, correlation coefficient r coefficient of determination R2 and the t-test t. Based on the statistical results a new linear model H/H0 =0.192+0.281(ΔT/S0) based on modified Angstrom model is recommended to estimate monthly average daily global solar radiation for Sokoto State areas and in elsewhere with similar climatic conditions where the radiation data is missing or unavailable. The present work will help to advance the state of knowledge of global solar radiation to the point where it has applications in the estimation of monthly average daily global solar radiation.