The literature on women’s under-representation in academia asserts that faculty women face a ‘chilly climate’, but there are few theoretically based studies examining this proposition. Relational demography, organizational justice, and social network theories all identify possible antecedents of ‘chilly climate’. Using survey data of faculty at a private Midwestern US university, we test whether the perception of exclusion (chilly climate) is influenced by demographic dissimilarity, and perceptions of fairness and gender equity. We find that faculty women perceive more exclusion from academic departments with a low representation of women, consistent with relational demography. Perceptions of procedural fairness and gender equity are powerful factors that foster inclusion and warm the climate for both men and women. The ‘chilly climate’ for women faculty is a complex phenomenon with multiple causes. Policies that fail to address these multiple causes are unlikely to be effective.