This metadata record describes the annual average number of occurrences of dry and wet events during the 30-year period 1981-2010 for the conterminous United States. A wet event is defined as a period when the number of consecutive days with precipitation equals or exceeds 1 millimeter. A dry event is defined as a period when the number of consecutive days with precipitation equals 0 millimeters. The source data was produced and acquired from DAYMET (2018) and is presented here as a 1-kilometer resolution GeoTIFF file.