West's Snow Drought Risk to Hit 87% by 2090s, Colorado Study Finds

The fragile snowpack of the American West is on a timer. New research from the Colorado School of Mines reveals that the extreme snow drought that gripped the region last winter was not an anomaly but a preview — climate change already boosted its likelihood fourfold, and by the 2090s, similar dry winters will be the norm 87% of the time. For climate and energy professionals, this study is a stark data point that underscores the urgency of both emissions reduction and adaptation planning in water-stressed basins.

A groundbreaking study led by the Colorado School of Mines, published in the Proceedings of the National Academy of Sciences, reveals that climate change has already dramatically increased the likelihood of extreme snow droughts like the one that parched the Western U.S. last winter. By analyzing historical data and climate models, researchers found that human-caused warming made the 2025–2026 snow drought four times more probable than during the preindustrial period (1850–1900). In the Upper Colorado River Basin, which spans nearly all of western Colorado, the influence was even starker — climate change made such a dry winter 14 times more likely. These findings quantify what many scientists and water managers have feared: the West’s snowpack, the region’s largest natural reservoir, is under existential threat.

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Lead author Adrienne Marshall, a computational hydrologist at the School of Mines, called the magnitude of the impact "a gut punch." She had anticipated a 20% to 30% increase in likelihood, not the many-fold jump the data showed.

Lead author Adrienne Marshall, a computational hydrologist at the School of Mines, called the magnitude of the impact "a gut punch." She had anticipated a 20% to 30% increase in likelihood, not the many-fold jump the data showed. The study translates these numbers into a grim timeline. Through the end of the current decade (around 2030), the chance of a repeat extreme snow drought will hover near 10%. By the 2050s, that risk jumps to 32%, and by the 2090s, it accelerates to 87%. In effect, what was once a rare event is on track to become the norm, occurring in nearly nine out of every ten winters if greenhouse gas emissions continue unabated.

The implications cascade across ecosystems, economies, and infrastructure. Last winter’s snow drought has already translated into extreme summer drought, depleted reservoirs, and mandatory water use restrictions across Colorado and the broader region. Wildfire risk has spiked as dry soils and vegetation persist, while recreational industries — from skiing to river rafting — face shortened seasons and reduced reliability. The snowpack acts as a slow-release water bank; its decline disrupts agriculture, hydropower generation, and municipal supplies that serve millions.