Global Climate Change The Exploratorium
home atmosphere hydrosphere cryosphere biosphere global effects

US Drought Monitor

Each color on this map represents a different intensity of drought conditions. Scientists determined regional intensities by first combining several drought indices—numbers that combine data on precipitation levels, soil moisture, stream flows, vegetation health, and more—and then making adjustments based on local moisture reports.

Many future-climate models predict that increasing global temperatures may lower precipitation in low- and mid-latitudes. Longer, more severe droughts may be part of the climate-change picture. To explore this possibility, experts are watching for changes in drought patterns around the globe.

Evaluating data over time may reveal long-term drought trends, allowing scientists to understand possible connections between drought and climate change. But such connections come with a measure of uncertainty: Topographical factors (such as mountains, coastlines, lakes, and soil types) play an important role in regional climates—so drought patterns in New England, for example, may be very different from drought patterns elsewhere. Many climate models do not consider these topographical factors, so it’s difficult to predict how global climate change may affect drought trends.

 glossary  glossary terms  

Click for definitions of words used on this page:

climate model

View the full, printable version of the glossary.

US Drought Monitor

U.S. Drought Monitor - This map provides a measure of the intensity of current drought conditions in the United States, with darker colors indicating more severe drought conditions. A new “Drought Monitor” map is created each week. Source: National Weather Service Climate Prediction Center

 questions about the data  

question Is continued global warming likely to lead to a greater chance of droughts worldwide? Won’t some areas get more rain than they do now, rather than less?

email Email your own questions about this data set. 

 research connection  

To make this map, scientists combined thousands of bits of data into single numbers called indices. This helped to simplify the map into a “big picture” tool that can effectively reveal broad climate trends. Researchers in many fields commonly boil down their data into indices to prevent their analyses from growing too complex—and to help them see the big picture.

 related sites  

Drought Watch - Links to drought-related sites from the National Drought Mitigation Center.

National Climate Diagnostic Center - Weather archives from the National Climate Diagnostic Center.

home | atmosphere | hydrosphere | cryosphere | biosphere | global effects

about this site - © 2002 The Exploratorium