The idea of compact cities is attracting enthusiasts, and some have proposed sustainable options for its implementation. This concept is based on planning for higher density cities with efficient connectivity in their structures. Because climatic characteristics are one of the basic factors to consider when planning a town, the models imported from different climates of Brazil must be intensely scrutinized and analyzed for their adequacy and effectiveness. Previous studies have revealed the inadequacy of the compact city model for tropical countries. In this study, the Copacabana neighborhood in Rio de Janeiro, a city that is currently compact, was assessed using computational tools (ENVI-met) to observe the intraurban temperature dynamics and sky view factor (SVF) alterations at three time-points’ unit occupation history: 1930, 1950, and 2018. To determine the effects of morphological changes on thermal sensation, two outdoor comfort indexes were calculated: the physiological equivalent temperature (PET) and the universal thermal climate (UTCI). From the obtained results, the relationship between urban morphology, air temperature, and thermal comfort indicates that the debate about urban models will be heightened, particularly with regard to the concept of compact cities in the formation of new cities and neighborhoods in the tropics.