Urban temperature is crucial to reach world sustainable development goals. This could affect building energy consumption and human thermal comfort, among other social, economic, and environmental issues. Meanwhile, cities can aggravate such problems by generating the phenomenon of urban heat islands (UHI). The main purpose of this research is to classify the urban form of Temuco city, Chile, and simulate the urban temperatures in several socioeconomic districts to understand how these differences could affect the neighborhoods in terms of house-building energy and thermal performance. For this, the local climate zone classification methodology was applied, then the urban weather generator (UWG) software was used to perform the different climate files. Also, data loggers were installed in the studied districts to validate the simulations in UWG. The results showed that low-income neighborhoods have higher UHI intensity reaching 9.5°C, while high-income neighbourhoods have UHI intensity as high as 5°C. These results can strongly affect the building energy performance in energy-vulnerable districts once all cities have the same energy and thermal official standards. Future investigations will be carried out to better understand how housing stock is affected.