U.S. Southwest megadrought persists, driven by climate change and disrupted Pacific cycle

September 18, 2026 at 10:00 PM2 min

This digest was compiled by AI from multiple sources — links to the originals are below.

The American Southwest is enduring a historic megadrought that scientists say is the driest the region has been in 1,200 years. Since 2000, the Colorado River's flow has decreased by roughly 20 percent, and Lakes Powell and Mead fell to historic lows in August. A 2025 study suggests human activity has disrupted a Pacific climate cycle that once brought wet weather to the region.

Key Facts

The current megadrought in the American Southwest is the driest the region has been in 1,200 years.
Since 2000, the Colorado River's flow has decreased by roughly 20 percent.
Lakes Powell and Mead fell to historic lows in August, at about a quarter of their combined capacity.
In August, the federal government cut river water allocations to Arizona, California, and Nevada by roughly 20 percent over the next two years.
A 2025 study in Nature suggests human activity has disrupted a Pacific climate cycle that historically brought wet weather to the Southwest.

Kearny's Water Crisis

Kearny, Arizona, a town of 2,000 people, sources its water from the Gila River. In March, snowpack feeding the river dropped to 1 percent of its historic norm, and the Gila River water commissioner cut Kearny's allotment by 85 percent. Town officials announced in April that 'Zero Day' was approaching, when taps would run dry. Norm Warren, owner of the only large grocery store within a 45-minute drive, said without tap water for cooling systems he cannot store perishable products.

Scientific Explanations

Scientists attribute the drought to rising temperatures and declining precipitation. Kevin Anchukaitis of the University of Arizona says heat from human-caused climate change creates a thirsty atmosphere that dries out the landscape. A controversial 2025 study in Nature suggests humankind has disrupted a naturally occurring Pacific climate cycle that historically brought wet weather to the Southwest. Brad Udall, a water and climate researcher at Colorado State University, says the drought is 27 years in and shows no signs of letting up.