This tabular data set represents the average number of consecutive days with measurable precipitation for the period between 1871 and 1997, compiled for two spatial components of the NHDPlus version 2 data suite (NHDPlusv2) for the conterminous United States; 1) individual reach catchments and 2) reach catchments accumulated upstream through the river network. This dataset can be linked to the NHDPlus version 2 data suite by the unique identifier COMID. The source data is from the United States Historical Climatology Network Daily Temperature, Precipitation, and Snow Data for 1871-1997, compiled by the Oak Ridge National Laboratory (ORNL, 1999) and further processed by the USGS (Dave Wolock, written communic., 2001). Units are days. Reach catchment information characterizes data at the local scale. Reach catchments accumulated upstream through the river network characterizes cumulative upstream conditions. Network-accumulated values are computed using two methods, 1) divergence-routed and 2) total cumulative drainage area. Both approaches use a modified routing database to navigate the NHDPlus reach network to aggregate (accumulate) the metrics derived from the reach catchment scale. (Schwarz and Wieczorek, 2016).