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.