Solar irradiation is the critical parameter required for the design of a solar conversion system but is not always available for the site under consideration. Empirical equations based upon data available at a second nearby site have, at times, been applied to fill this void. The aim of this study is to evaluate the accuracy of an empirical correlation to estimate solar irradiation, based upon a single commonly measured parameter, average daily dry bulb temperature, and the calculated extraterrestrial irradiation, developed for a single site and applied to nearby sites. The per cent mean bias error (%MBE) for the five sites studied is in the range of -6.59 - 1.68%, whereas the per cent root mean square error (%RMSE) is in the range of 13.58-16.95%. The prediction accuracy of the empirical correlation as given by the mean absolute percentage error (MAPE) is in the range of 14.53-21.09% and the correlation coefficient is in the range of 0.917-0.925. The prediction accuracy of this relatively simple, single parameter correlation developed for a single site and then applied to five nearby sites compares favorably with that for more complicated multi-parameter generalized correlations. (C) 2020 Elsevier Ltd. All rights reserved.