Drought is one of the costliest and slowest-moving natural disasters, and the U.S. Drought Monitor has tracked it week by week since 2000. At its worst, more than half the country has been in drought at the same time. This guide charts a quarter-century of U.S. drought, explains the D0–D4 severity scale, and looks at the long Western megadrought that has reshaped water policy across the American West.
How much of the U.S. is in drought?
The chart shows the share of U.S. land area in drought, broken into severity bands. The lines are cumulative — the "moderate or worse" line includes everything more severe than it. The total swings dramatically with the seasons and with multi-year wet and dry cycles: in a wet year only a small fraction of the country is dry, while in a bad year — like 2012 or the early 2020s — drought can cover well over half the land area at once.
The drought severity scale (D0–D4)
The Drought Monitor rates conditions on a five-step scale. D0 is "abnormally dry" (not yet drought, but heading there); D1 is moderate drought; D2 severe; D3 extreme; and D4 is "exceptional drought," the rarest and most damaging category, where crop and water losses are widespread and emergencies are common. The scale combines rainfall, soil moisture, streamflow, and expert judgment into a single weekly map.
The Western megadrought
The defining drought story of the era is the Western megadrought — a multi-decade dry spell across the Southwest that scientists consider the driest such stretch in well over a thousand years. It drained the nation's largest reservoirs, Lake Mead and Lake Powell, to record lows and forced unprecedented cuts to Colorado River water allotments. Spikes in the extreme and exceptional drought lines during the early 2020s reflect this crisis.
Why drought matters
Drought ripples through the whole economy. It cuts crop yields and drives up food prices, strains water supplies for cities and farms, lowers rivers used for shipping and hydropower, and dramatically raises wildfire risk. Because it builds slowly and lingers, drought is easy to underestimate — but it's among the most expensive weather disasters the U.S. faces, and a warming climate is making severe droughts more frequent and intense in many regions.
Frequently asked questions
How much of the U.S. is in drought right now?
It varies week to week — see the chart above for the current share. In bad years, drought has covered more than half the country at once.
What do D0 to D4 mean?
They're the Drought Monitor's severity levels: D0 abnormally dry, D1 moderate, D2 severe, D3 extreme, and D4 exceptional — the rarest and most damaging category.
What is the Western megadrought?
A multi-decade dry spell across the U.S. Southwest, considered the driest such stretch in over a thousand years. It drove Lake Mead and Lake Powell to record lows.
When was the worst recent U.S. drought?
Major peaks came in 2012, when drought covered much of the country, and during the early-2020s Western megadrought. The 25-year record is shown above.
Where does drought data come from?
From the U.S. Drought Monitor, a weekly map produced jointly by the National Drought Mitigation Center, USDA, and NOAA.