The study aimed to identify areas at risk of desertification in the semi-arid state of Sergipe by using the aridity index. This index was based on monthly data of rainfall and temperature, categorizing areas as hyper-arid, arid, semi-arid, sub-humid dry, or sub-humid and humid. The northwest region of Sergipe showed the highest aridity index and the highest risk of desertification, particularly in the semi-arid classification. Some regions experience monthly aridity, increasing their susceptibility to desertification.