This study investigates the influence of individuals’ social connections in their decision to either evacuate or not evacuate in the days preceding the landfall of Hurricane Irma. Using Hurricane Irma in September 2017 as a case study, a survey was conducted on two groups (those who evacuated and those who did not evacuate) to assess people’s social connections specifically examining three dimensions: dependability, density, and diversity. These variables, together with socioeconomic variables (e.g., race/ethnicity, age, education), were considered in order to better explain the influences on evacuation decision-making. To collect accurate ephemeral decision-making data from evacuees, the surveys were completed during the evacuation for those who evacuated and shortly after the passage of Hurricane Irma for those who did not evacuate. Through statistical analyses, it was concluded that density and diversity of people’s social networks played a significant role in the decision to evacuate or not, with evacuees having more dense and diverse relationships. On the other hand, the perceived dependability of a person’s social connections (i.e., their perceived access to resources and support) did not significantly impact the decision to evacuate for Hurricane Irma. This study has important implications for adding to the knowledge base on community-based sustainable disaster preparedness and resilience.