United States Drought Monitor (USDM)

The U.S. Drought Monitor, established in 1999, is a weekly map of drought conditions that is produced jointly by the National Oceanic and Atmospheric Administration, the U.S. Department of Agriculture, and the National Drought Mitigation Center (NDMC) at the University of Nebraska-Lincoln. The U.S. Drought Monitor website is hosted and maintained by the NDMC.

U.S. Drought Monitor maps come out every Thursday morning at 8:30 Eastern Time, based on data through 7 a.m. Eastern Standard Time (8 a.m. Eastern Daylight Time) the preceding Tuesday. The map is based on measurements of climatic, hydrologic and soil conditions as well as reported impacts and observations from more than 350 contributors around the country. Eleven climatologists from the partner organizations take turns serving as the lead author each week. The authors examine all the data and use their best judgment to reconcile any differences in what different sources are saying.

Countries around the world have sought to emulate the U.S. Drought Monitor. We stress that it isn’t a strictly quantitative product, and that the community of drought observers lends credibility to the state-of-the-art blend of science and subjectivity that goes into the map.

The U.S. Drought Monitor, a composite index that includes many indicators, is the drought map that policymakers and media use in discussions of drought and in allocating drought relief. The U.S. Department of Agriculture’s Farm Service Agency used the U.S. Drought Monitor to distribute an estimated $1.64 billion from 2008 to 2011 through the Livestock Forage Disaster Program; $50 million in 2007 through the Livestock Assistance Grant Program; and additional funds through the Non-Fat Dry Milk Program in 2003 and 2004. The Internal Revenue Service also uses the U.S. Drought Monitor to determine the replacement period for livestock sold because of drought. As part of its response to the drought of 2012, the U.S. Department of Agriculture streamlined the process for secretarial disaster declarations, making declarations nearly automatic for a county shown in severe drought on the U.S. Drought Monitor for eight consecutive weeks.