Data from a precipitation gauge network on the WE-38 Experimental Watershed. The U.S. Department of Agriculture (USDA) Agricultural Research Service (ARS) Pasture Systems and Watershed Management Research Unit (PSWMRU) operates a precipitation gauge network on the WE-38 Experimental Watershed to support long-term intensive research on the impacts of agriculture on water quality in the northeast United States. The WE-38 Watershed is situated within the Northern Appalachian Ridges and Valleys Province and drains 7.3 km2 of mostly rolling farmland within the northern portion of the Mahantango Creek Watershed, a 420 km2 tributary to the Susquehanna River about 48 km north of Harrisburg in Northumberland County, Pennsylvania. In 1966, scientists from the Northeast Watershed Research Center (NWRC) established an intensive rainfall monitoring network throughout Mahantango Creek Watershed, consisting of 43 rain gauges located to provide uniform aerial coverage and characterize the full range of elevations in Mahantango Creek Watershed. In 1996, the advent of data-logging and measurement technology made it possible to upgrade the existing network of Fischer-Porter rain gauges. The digital punch paper tape system (drive shaft and gears) and weighing mechanism on each Fischer-Porter gauge were replaced with an Interface (Model SSB-AJ-100) load cell and connected to a Campbell CR10X data logger. The load cell data-logging system, which is still in use today, records accumulated precipitation every 5 minutes to the nearest 0.254 mm.