Drought levels across most of the southwest and California are at the worst level in decades. In some cases, the problem is the worst it has been in a century. There is no sign it will let up in the foreseeable future, leaving tens of thousands of square miles unable to support crops and livestock and scores of cities without enough water to support their populations.
One state, Utah, is worse off than the rest although states adjacent to it have problems nearly as severe.
The gold standard for measuring drought conditions is the U.S. Drought Monitor, which is a joint venture among the National Drought Mitigation Center at the University of Nebraska-Lincoln, the United States Department of Agriculture, and the National Oceanic and Atmospheric Administration.
The monitor ranks drought severity in states by combining five categories of drought D0 to D4, with D4 as the worst level. To identify the states hit hardest by drought, we compared every state’s Drought Severity and Coverage Index (DSCI).
For reference, the year-to-date average DSCI for the continental United States is about 169. The DSCI value for the latest week of data, starting June 8, is 170. The average DSCI value for the continental U.S. has not fallen below 164 during any week of 2021. At around this time last year, the week of June 16, 2020, the DSCI value was lower by nearly half, at 79. Only six states are completely drought-free. The value for Utah is 452.
D0 is described as places where “dryland crops are struggling” and “water for cattle is limited.” D1 drought levels are where “soil moisture is low and winter wheat germination is poor.” D2 is described as where “pasture and water is inadequate for cattle” and “streams and ponds are dry.” D3 is described as places where “fire danger increases” and “native vegetation is stressed.” And D4 is the designation for places where “fire restrictions increase” and “irrigation water allotments are cut.” D4 areas are also labeled places with “exceptional drought.”
A recent New York Times article that examined the issue attributes much of the trouble to climate change. “But at the root of the drought are warmer temperatures and changing precipitation patterns, which are linked to emissions of carbon dioxide and other greenhouse gases into the atmosphere, where they trap the sun’s heat.”