This article describes an engaging, data-gathering activity that allows students to explore relationships between latitude and average monthly temperatures of cities in the Western Hemisphere. This data-gathering activity covered interesting and important mathematical ground and engaged students from the start. While students searched for their list of cities, the authors overheard them asking questions and exchanging ideas related to the geographical properties of the cities they chose. The introductory data-gathering portion of this activity piqued students' interest and provided the basis for mathematical relationships they found between latitude and temperature. (Contains 5 tables and 9 figures.)