When to Plan Outdoor Activities: The Daytime and Seasonal Patterns of Wetness in the Southeastern United States

Most areas of the southeastern United States enjoy a mild climate that supports numerous outdoor activities. Wet conditions associated with the occurrence of precipitation, however, can disrupt or force the cancellation of these activities. In this study, a wetness climatology is developed for the region that emphasizes the identification of relatively dry and wet periods for guidance in the planning of outdoor activities. Hourly wetness probabilities are calculated for each month of the year and used to identify daytime and seasonal periods in which the probabilities of wet conditions are maximized and minimized. On a seasonal time scale, the probabilities of wetness are found to be lowest in autumn and greatest in winter. Regional variations are observed in this pattern, however, especially in the southern portions of the region. During the daytime, a marked cycle of wetness is identified during the summer that consists of a wetness minimum in the morning and a maximum in the afternoon to early evening. The timing and magnitude of this wetness cycle shows considerable variation across the Southeast.