Enthalpy is currently suggested as a suitable index for assessing the internal environment of poultry production, primarily dependents on air temperature and relative air humidity. This study aimed to analyze enthalpy in bird production in Londrina, located in the northern region of Paraná, Brazil, and to model the comfort enthalpy required for enhanced production efficiency. Data from 1961 to 2021 from the Instituto Nacional de Meteorologia (INMET), Brasília, Federal District, Brazil, were utilized to compare the thermal comfort conditions and critical limits set for the birds. The meteorological data from this period were scrutinized to understand their variations and interrelationship through a descriptive study and correlation analysis of different parameters. The research findings, based on the enthalpy indices derive historical averages, suggest that heating is crucial for birds during the first and second weeks of housing, during the winter, given the location’s low temperatures. For birds housed during the third to sixth weeks of age, the enthalpy indices indicated the necessity of cooling systems.