This paper delves into the significance of naturally ventilated spaces in globally significant cities such as Chica-go, Lahore, and Saskatoon. The analysis was based on TMY annual weather data. A future weather generator was employed to project weather data for two future climates, the reference year 2050 (2036–2065), with two Shared Socioeconomic Pathways (SSP); these are: A simulation program calculates the dry-bulb and operative temperatures and airflow for each hour of the month in a space. The results from this bulk air analysis are fed into a spreadsheet for post-processing. The data is sorted into workdays and hours of occupancy and then evaluated for compliance with the comfort thresholds. The results of this study demonstrate compliance with ASHRAE Standard 55 Section 5.4 for present-day weather and weather predicted for 2050. Specifically, this research highlights the influence on occupant-controlled naturally conditioned spaces under future climates. This practical application of our findings can significantly impact the audience’s work in the field. This research is crucial in the global context of sustainable building design and climate change adaptation.