Recent research has demonstrated the adaptiveness of variability in emotion regulation (ER) by showing that variability between and, when controlled for depression, within ER strategies as assessed via the standard deviation was associated with less negative affect. We first replicated associations with negative affect by using the relative standard deviation, which is less confounded with the mean. Second, following research on affect dynamics, we extended this line of research by examining five additional ER dynamic measures covering ER instability, inertia, predictability, differentiation, and diversity. Reanalyzing data from five ambulatory assessment data sets (N = 717), we found that (a) the eight ER dynamic measures loaded on five factors that explained unique variance, (b) most ER dynamic measures had good reliabilities, and (c) between-strategy mean endorsement was positively, whereas between-strategy variability and ER predictability were negatively associated with negative affect. These results suggest that the variable but predictable use of emotion regulation strategies in daily life is beneficial for individuals' affective well-being in daily life. (PsycInfo Database Record (c) 2022 APA, all rights reserved).