OBJECTIVE: Drinking intention is a predictor of heavy-drinking episodes and could serve as a real-time target for preventive interventions. However, the association is inconsistent and relatively weak. Considering the affective context when intentions are formed might improve results by revealing conditions in which intention-behavior links are strongest and the predictive power of intentions is greatest. METHOD: We investigated the links between drinking intentions reported in the morning and same-day drinking behavior, moderated by positive and negative affect (PA, NA) in a sample of heavy-drinking young adults. Participants wore the SCRAM continuous alcohol monitor transdermal alcohol sensor anklet for 6 consecutive days in their natural environments and responded to daily ecological momentary assessments that included morning intentions to drink and PA/NA items. Drinking events and patterns were measured using morning-report counts and features from the sensor. Bayesian gamma-hurdle and Poisson multilevel models with noninformative priors tested day-level associations. We hypothesized that drinking intention-behavior associations would be strongest on days with high levels of PA, but we did not hypothesize directionality for the NA effect given the conflicting results in previous literature. RESULTS: Day-level drinking intention-behavior associations were stronger on days with higher versus lower PA according to sensors features. Associations were also stronger on days with lower versus higher NA. CONCLUSIONS: The strength of intention-behavior links may partly depend on the affective contexts in which intentions are formed. Results could fine-tune intervention approaches by elucidating the affective contexts in which intentions may more clearly link to drinking behavior to reduce the intensity of an episode-better anticipating problematic drinking among young adults. (PsycInfo Database Record (c) 2025 APA, all rights reserved).