The aim of the research was to evaluate the temporal variability of the solar radiation and insolation in Araguaína-TO. The meteorological data (insolation and cloudiness) had been gotten of the conventional station of the INMET, located in the campus of “Medicina Veterinária e Zootecnia”. The global solar radiation (Qg) was gotten by means of images of satellite GOES and from this the total of the solar radiation reflected (Qr) and absorbed was calculated (Qa). The established Albedo was of 0,3% of reflectivity. The biggest incidences of the Qg and the insolation had been verified in the months of April, May, June, July, August and September, coinciding with the period of lesser local cloudiness. The amplitude of annual variation of the cloudiness in the region is relatively high, varying from 1 to 8/10 throughout the year.