This study examined the social climate of fully synchronous online English classrooms and its effects on students' learning outcomes in a mixed-methods design, engaging 196 first-year non-English major students experiencing their first fully synchronous online English classes on Zoom in one academic term (12 weeks), taught by foreign lecturers. The results reveal a very positive learning experience with seven factors contributing to the social climate of the online English classrooms. Gender did not affect students' perceptions and learning experiences, but English proficiency levels did, with a medium effect size. The social climate was a predictor of online English learning outcomes with a substantial effect size. Individual insights were extracted from the qualitative data.