This dataset adds attributes describing the self-calibrated Palmer Drought Severity Index (PDSI) during the observation year of wet/dry streamflow observations collected in the Pacific Northwest, USA. Streamflow observation locations are linked to the nearest National Hydrography Dataset high-resolution (NHD-HR) stream segment to obtain stream order and stream permanence (perennial/non-perennial) from NHD-HR. Additionally, the PDSI and precipitation percentile for 7.5 minute quadrangle map extents, within the extent of the conterminous United States (https://carto.nationalmap.gov/arcgis/rest/services/map_indices/MapServer), during the map survey year are presented. NHD perennial/non-perennial classifications derive from the topographic maps.