Due to changes in state and federal policies, as well as logistical and fiscal limitations, researchers must increasingly rely on teachers' reports of school climate dimensions in order to investigate the developmental impact of these dimensions, and to evaluate efforts to enhance the impact of school environments on the development of young adolescents. Teachers' climate ratings exhibited a robust dimensional structure, high levels of internal consistency, and moderate levels of stability over 1- and 2-year time spans. Teachers' climate ratings were also found to be related consistently with students' ratings. In three large-scale samples of schools, teachers' climate ratings were associated significantly and consistently with students' performance on standardized tests of academic achievement, and with indexes of their academic, behavioral, and socio-emotional adjustment. (Contains 9 tables.)