Abstract The thermal performance of buildings can be evaluated prior to its construction by modeling it using a specialized software. Climate boundary conditions must be represented by a weather file that is composed of a weather dataset organized hourly according to a defined year structure such as Test Reference Year (TRY) or Typical Meteorological Year (TMY). Before this study, there were a few weather files available for cities in southern Brazil, notably, Santa Maria, RS, classified as a humid subtropical climate. The most recent available weather file was built in 2014 and presents inconsistencies with respect to precipitation data. Therefore, the objetive of this study was to process and analyze the climate data of Santa Maria over an eighteen-year period (2002-2020), to generate a more reliable weather file. The applied method considered the following procedures: data collection and processing; TRY (TRY17) and TMY2 (TMY0220) definition; solar radiation data calculation; EPW files generation; and comparison between the new EPW files and the previous existing files. As a result, in a short period of time (2014-2020), significant differences among the weather files were observed. The importance of updating weather files in time intervals shorter than 30 years was emphasized. In relation to the comparative analysis, both weather files (TRY17 and TMY0220) presented dry bulb temperatures in consonance with the other files previously available. Although, the correction of precipitation data could originate building simulations closer to the reality. software (TRY TMY. TMY . (TMY) Brazil notably RS 201 Therefore eighteenyear eighteen 20022020, 20022020 2002 2020 , (2002-2020) procedures processing TRY17 TMY0220 (TMY0220 definition calculation generation result 20142020, 20142020 (2014-2020) observed 3 emphasized analysis (TRY1 Although reality (TMY 20 2002202 200 202 (2002-2020 TRY1 TMY022 (TMY022 2014202 (2014-2020 2 200220 (2002-202 TMY02 (TMY02 201420 (2014-202 20022 (2002-20 TMY0 (TMY0 20142 (2014-20 (2002-2 (2014-2 (2002- (2014- (2002 (2014 (200 (201 (20 (2 (