College sense of belonging and well-being constitute critical components of college student adjustment and success. Previous studies have generally measured these outcomes at one (or sometimes two) points in time, which prevents researchers from understanding the ongoing adjustment process as well as the dynamic interplay between college experiences and outcomes. This study provides unique insights by examining week-by-week data that consisted of 12,529 total responses from 882 undergraduates during their first semester of college. Fixed-effects regression analyses were used to examine the extent to which weekly changes in students' experiences and interpersonal relationships predicted corresponding changes in adjustment outcomes. Social connection, relationship satisfaction with college friends, and feeling successful in class were most strongly related to changes in belonging and well-being. Some experiences that are often overlooked in higher education research were also significant predictors; specifically, time spent exercising and relationship satisfaction with parents were associated with more favorable outcomes, whereas extensive social media use was associated with poorer outcomes. Implications for research and practice are discussed.