Emotional stability, as indicated by low affect variability and low affective reactivity to daily events, for example, tends to increase across the adult life span. This study investigated a contextual explanation for such age differences, relating affect variability and affective reactivity to age-group-specific life contexts. A sample of 101 younger and 103 older adults reported daily stressors and negative affect across 100 days. Compared with younger adults, older adults (a) experienced fewer stressors overall, (b) had less heterogeneous stressor profiles, and (c) reported that stressors had less impact on daily routines. As expected, these contextual factors were relevant for interindividual differences in emotional stability. Multiple regression analyses revealed that reduced affect variability and affective reactivity in older adults were associated with these age-group specific life contexts. Moreover, matching younger and older adults on the contextual factors to explore the effects of context on age-group differences further provided support for the (partially) contextual explanation of age differences in emotional stability. Matched subgroups of younger and older adults that were comparable on contextual variables were identified. Affective variability, but not affective reactivity, was more similar in the matched subsamples than in the total samples of younger and older adults. We conclude that contexts in which affective experiences emerge require more attention when aiming to explain interindividual and age group differences in emotional stability. Moreover, future studies need to disentangle the extent to which contexts interact with active self-regulatory processes to shape affective experiences across adulthood.