The current study examined adolescent psychological reactivity to daily family experiences, an important feature of emotion regulation that could have significant implications for psychopathology. A total of 428 Mexican‐heritage adolescents (M
age = 15.02 years, range: 13–18 years) completed daily diary checklists for 14 days and again 1 year later. Results revealed that adolescents’ family experiences were associated with negative mood, positive mood, and role fulfillment on a daily basis. Only role fulfillment reactivity was stable across 1 year, suggesting instability in individual differences in positive and negative mood reactivity. Sex moderated the relation between positive and negative mood reactivity during the second year of study, with males exhibiting broad psychological reactivity to daily family experiences. However, females who experienced higher negative mood reactivity exhibited less positive mood reactivity. Implications for possible sex differences in depression risk during the high school years are discussed.