Emerging evidence suggests that family members’ stress and family interactions vary across days. This study examined the daily associations among parental and adolescent daily stress, parental warmth, and adolescent adjustment with a 30-day daily diary study among 99 ethnically diverse Canadian parent–adolescent dyads (54% White, 23% Asian, 9% multiracial, Mage = 14.5, 55% female). Multilevel structural equation modeling revealed a negative within-day link between parental daily stress and parental warmth, and positive within-day links between adolescent daily stress and their emotional problems and negative affect. Parental warmth was positively associated with the next day’s adolescent positive affect and prosocial behaviors, and explained the cross-day link between parental daily stress and adolescent adaptive outcomes. The findings indicate parent-driven effects in daily family stress processes.