The goal of this study was to examine the relations among various meteorological conditions, affective states and behavior in young children. Results from past research have revealed many weather effects on behavior and emotions with adult samples. However, there is a paucity of empirical evidence to support this link with children. Thirty-three mothers were asked to rate their children (age 36-70 months) for a one-month period to assess positive and negative affect. Teachers completed questionnaires for the same period to assess internalizing (e.g. anxious), externalizing (e.g. aggressive) and prosocial (e.g. helping) behavior, and data were collected for various weather conditions. Pearson correlation analyses revealed many associations between weather and children?s internalizing, externalizing and prosocial behavior. Furthermore, using a moderated model approach, the interactions between weather (temperature, humidity and amount of sunshine) and children?s affect (positive and negative) were examined in the prediction of social adjustment in preschool. The overall pattern of results revealed that favorable temperature and an increased amount of sunshine promote positive social behaviors in children who are prone to higher levels of negative affect. However, the results also suggest that higher humidity is associated with decreases in prosocial behavior and increases in externalizing behavior in children who typically exhibit positive social adjustment. Findings are related to issues surrounding family functioning, classroom management and peer relations.