The mean monthly MPE determined in

The mean monthly MPE determined in this study is 0.51%, while based on the original Hargreaves equation, Dike et al. [17] reported mean MPE of 3.72% for the same location considered in this study. In general, the relative humidity based models (3 and 6) are less accurate than the other models. The sunshine hour based model is the most accurate of all the models; follow by the precipitation based model (Model 7). The RMSE value for Model 7 is 0.278. The average temperature based model and Hargreaves based model are third and fourth best respectively. Therefore, in the absence of the sunshine hour information, these models (2, 4 and 7) can be used to determine the global solar radiation for Akure and other similar locations.