Prolonged exposure to UV radiation is harmful and causes skin cancer. Currently, interested people get their UV radiation information from the weather forecast, which has a rough estimate and average for a given region. The research focuses on developing a mobile application using the mobile application development methodology with the objective of calculating UV index values in real time, considering the geographical position and time. The evaluation of the values calculated by the mobile application were validated by linear correlation with data obtained by the TUV model and measured by the meteorological station, obtaining values greater than 0.993 for both comparisons. It is determined that extreme values are presented between the hours of 11am to 14pm. Concluding that it is possible to implement mobile applications to determine UV index values for the Puno region.