People experience momentary fluctuations in how much they differentiate between emotions and how clear they are about what they are feeling. To better understand situational predictors of shifts in emotion differentiation and emotional clarity, we investigated whether individuals are more differentiated and clearer about their emotions in social situations (vs. alone) given that emotions fulfill important social functions. We tested if these within-person associations varied depending on socially relevant individual differences, including age, extraversion, and social connectedness. We also examined whether people are more differentiated and clearer in situations that have previously been processed (i.e., familiar situations) and if this effect was stronger for older (vs. younger) adults. Community adults (N = 290, aged 25-85 years) completed measures of extraversion and social connectedness and then were randomly prompted 6 times a day for 10 days to report on their current emotional experience and situation. Using multilevel structural equation modeling, social context was associated with less positive emotion differentiation and not associated with emotional clarity; these within-person associations did not differ by age, extraversion, or social connectedness. Individuals experienced more differentiated positive emotions and higher emotional clarity than usual when they were in more (vs. less) familiar situations. Familiarity was especially predictive of higher positive emotion differentiation among relatively older (vs. younger) adults. These findings suggest positive emotion differentiation, particularly in familiar situations could be a way in which the quality of one's emotional experience changes with age. (PsycInfo Database Record (c) 2023 APA, all rights reserved).