Mounting research shows that high-quality social interactions with weak ties, such as acquaintances and strangers, confer myriad benefits. Episodes of positivity resonance – interactions marked by shared positive affect, caring nonverbal synchrony, and physiological synchrony – predict long-term health and longevity (Wells et al., 2022), prosociality (Zhou et al., 2022), and even adherence to pandemic hygiene behaviors (West et al., 2021). Positivity Resonance Theory posits that psychological safety is conducive for positivity resonance to emerge (Fredrickson, 2016). Yet, limited empirical research has tested this hypothesis. Little is also known about how positivity resonance with weak ties may vary across social identities, particularly among people who experience less psychological safety in certain social contexts. We test for relationships among psychological safety, anticipated identity-related discrimination and stigma, and positivity resonance, using a longitudinal dataset collected in North Carolina and representative of the state by race, gender, age, and socioeconomic status (N = 1,500). Across three consecutive months, participants reported on one salient social interaction with a weak tie. We find that experiences of psychological safety and positivity resonance vary within and across people. On average, when people experience more psychological safety during a social episode than is typical for them, they tend to experience more positivity resonance with weak ties during that episode. We also find that, on average, people who anticipate less identity-related stigma and discrimination from strangers also report higher positivity resonance with weak ties (between-person effects). Similarly, historically advantaged groups (including white and higher socioeconomic status individuals) on average report more psychological safety in social episodes with strangers and acquaintances. Lastly, anticipated stigma and discrimination moderates the effect of safety on positivity resonance, such that episodic safety has the largest impact on positivity resonance among people lowest in anticipated stigma and discrimination.