Methods of measuring and results of analyses of data spanning a period of two years on global solar radiation, global photosynthetically-active radiation (PAR) and downward infrared radiation at Ilorin, a tropical location, are presented. The results show that there exist seasonal tendencies in the variation of these radiations, especially for global solar radiation and PAR. The distribution and range of variation of global solar radiation show that Ilorin has a high potential for solar energy utilization while those of PAR indicate the availability of this very important radiation throughout the year, perhaps with the exception of the months of July and August. For downward infrared radiation, the results show that it is almost uniform throughout the year with the exception of the relatively small values in the Harmattan months (December and January) of the dry season.