Monitoring Tools

U.S. Drought Monitor & Related Products

U.S. Drought Monitor

The U.S. Drought Monitor is a weekly assessment of the extent and severity of drought in the United States.

The Drought Impact Reporter is a historic archive of the effects of drought, based mainly on media reports and volunteers’ observations. It’s a good starting point if you want to see how drought has affected people’s livelihoods and the environment in your area since 2005.

North American Drought Monitor

The North American Drought Monitor, produced monthly, shows the area and intensity of drought.

U.S. Agricultural Commodities in Drought

We overlay the U.S. Drought Monitor on agricultural census data to determine what proportion of different crop-producing areas are affected by drought.

Choose a Drought Indicator

Handbook of Drought Indicators and Indices

For a list of the pros and cons of 50 different drought indicators in use around the world, please refer to the Handbook of Drought Indicators and Indices. It was developed by Mark Svoboda and Brian Fuchs of the National Drought Mitigation Center at the University of Nebraska-Lincoln, and published in 2016 by the World Meteorological Organization and the Global Water Partnership.

Historic Data & Information

Drought Risk Atlas

The Drought Risk Atlas provides a historic look at drought for a specific location, going back as far as we have good data. See or download precipitation, temperature, or several different drought indices, including the U.S. Drought Monitor, the Standardized Precipitation Index and the Palmer Drought Severity Index.

Historical PDSI Maps

The Palmer Drought Severity index has been calculated by climate division for several time periods starting in 1895.

PDSI by River Basin

Select a river basin to view a graph of the Palmer Drought Severity Index from 1895 to 2004.

Satellite, Climate & Biophysical Data Products

Vegetation Drought Response Index

The Vegetation Drought Response Index combines data from satellites with ground-based measurements and other information to detect drought’s effects on vegetation.

Quick Drought Response Index

The Quick Drought Response Index detects “flash drought,” when heat and dryness combine to change environmental conditions over a few days or a few weeks.

Soil Moisture Detection

Groundwater and Soil Moisture Conditions from GRACE Data Assimilation

NASA’s GRACE satellite mission provides data on how much water is beneath the Earth’s surface. We use it to map soil moisture, root zone moisture and groundwater.

Soil Moisture Active Passive

Experimental maps based on data from NASA’s Soil Moisture Active Passive mission show changes in soil moisture over one week, one month and three months.

Standardized Precipitation Index

Standardized Precipitation Index by Climate Division

Download the program to compute the Standardized Precipitation Index with your data, or view archived SPI maps. The SPI tells you whether an area is dry or wet based on its historic record, and can be computed for different time intervals.