Depressive emotions and behaviors, such as sadness, irritability, and sleep difficulties, are often early-emerging, impairing, and persistent. However, these behaviors are normative in early development, so it is critical to identify the spectrum of behaviors that may be relevant to the development of depression. This study characterizes the frequency and severity of depressive behaviors and impairment in preschool-aged children using a novel daily diary method with 291 parents. A coherent depression dimension was identified, and the specific frequency at which individual behaviors were identified as severe is reported. Behaviors such as sadness, irritability, and tearfulness/sensitivity were found to be relatively normative, whereas other behaviors (e.g., low interest/pleasure, low self-worth) were less normative. These are the first known data to delineate empirical information about the frequency and severity of behaviors that may be relevant to the development of depression; such data provide quantitative information for child practitioners to make distinctions between developmentally typical and problematic behavior, which is essential for improving assessment and minimizing impairing developmental trajectories.