Drought Monitor -- A joint website of the U.S. Department of Agriculture, the National Oceanic and Atmospheric Administration, and the National Drought Mitigation Center.
National Drought Mitigation Center -- A University of Nebraska at Lincoln website.
North American Drought: A Paleo Perspective -- A National Oceanic and Atmospheric Administration website.
U. S. Drought Assessment -- A National Weather Service website produced by the Climate Prediction Center.
U.S. Drought Portal -- A National Integrated Drought Information System website.