After observing the behaviour of the global solar radiation and the UV index, through the information collected by the meteorological station DAVIS vantage PRO 2.0 in the city of Pasto, WGS84 coordinates: 1.20851008 -77.27805080 latitude and longitude, during the years 2013 to 2016, an accentuated correspondence between the two variables was noted. Therefore, the UV index was treated with a polynomial function to estimate the global radiation signal incident at the sample time, the correlation factor is 0,9642 and the RMSE is 30,90. The evaluation uses random signals and shows an accurate model response. This could be an economical alternative foirradiance sensing, because UV radiation sensors are cheaper than global radiation.