Even in "routine" years, the principal's attention to climate matters for wellness, and it matters for outcomes. School climate is a critical factor supporting the quality of student learning, particularly in times of stress. As a result, districts across the nation have dedicated considerable resources to tools used to assess climate, most often surveys that ask how students, parents, or staff are experiencing the school. Climate data has untapped potential as a tool not only to describe perceptions, but also to energize improved experiences. This toolkit is for principals, rooted in the experiences of fellow school leaders who are taking concrete, accessible action with climate data. The Aspen Education & Society Program convened principals, districts, and research partners to identify opportunities to enhance that action. The initial series of school visits and interviews ran into the COVID-19 detour, but continued virtual collaboration has strengthened the belief that climate data is useful for building transparency and insight, deepening relationships, and inspiring collective action. Several strategic themes emerged as valuable opportunities for principals: (1) using climate data to drive toward equitable outcomes; (2) creating routines to lead with data; and (3) choosing the right starting points. The strategies and tools offered under each theme are based on in-school observations and input from research partners, consulting experts, students, and faculty. Each reference and link points principals to research and tools that can be used in school this fall. The year ahead will be rich with opportunities to deepen principals' repertoire for welcoming students into school. [This report was produced in collaboration with Cleveland Metropolitan School District, Tulsa Public Schools, Turnaround For Children, EduDream, and National Equity Project.]