This article aims to analyze the thermal comfort of the courtyard/cafeteria of the Monsenhor José Gerardo Ferreira Gomes Full-Time High School (EEMTI), from the perspective of the Discomfort Index (DI). The research was guided by the theoretical assumptions defined by Professor Carlos Augusto de Figueiredo Monteiro (2003), who defined a theoretical and methodological framework for the understanding of the urban factor, through the Urban Climate System (UCS). The aforementioned school, located on the outskirts of the city of Sobral/CE--Brazil, underwent changes in its teaching modality in 2017, changing to the full-time education system, where students remain at school all day, eating three meals. However, the building, even though it has undergone some adaptations for this new modality, is the same as when it was inaugurated in 1977. This fact, associated with the local environmental conditions of hot semi-arid climate, typical of the Brazilian Northeast, makes it difficult for students to accommodate and remain in outdoor spaces. The results collected and the DI analysis indicate a situation of thermal discomfort in most of the times analyzed, even though the research took place in the rainy season for the region, which presents a lot of cloudiness and milder temperature conditions.