Colorado experienced its warmest water year on record during the 2025-26 period, with an average temperature two degrees Fahrenheit above the previous record set in 1934. This extreme warmth was detailed in a new report from Colorado State University (CSU) researchers, which also highlighted the lowest mountain snowpack ever recorded.
The 2025-26 water year, which spans from October to September, concluded with statewide conditions described as "one for the record books in Colorado." According to the CSU report, it was the state's "warmest on record by a substantial margin," and simultaneously one of the driest. The historically low mountain snowpack has significant implications across multiple sectors, including agriculture, wildfire risk, human health, and recreation.
The extraordinary temperatures were evident throughout the year, with four months—December, January, March, and August—ranking as the warmest ever for those respective months. Furthermore, 11 of the 12 months in the water year ranked among the top-15 warmest on record. Statewide, temperatures averaged 4.5 degrees Fahrenheit above the averages observed between 1991 and 2020.
CSU researchers found that daily warm records, encompassing both record high temperatures and record warm lows, occurred 21.7 times more frequently than cold records, marking the most unbalanced ratio ever recorded. The hottest single day for Colorado occurred on July 27, surpassing the previous record set on July 21 of the preceding year. Additionally, one warmest-ever day was set in October, two in December, nine in March, and three in August.
Evidence of this exceptional warmth was observed across the state. In Meeker, a resident noted that nights stayed warm enough to allow tomato growth, which is typically prevented by colder overnight temperatures. Larry Zaragoza, then the town manager of La Jara, in the San Luis Valley, spoke of the extreme warmth, detailing how he cultivated a robust corn crop in his backyard garden, a feat he had only achieved once before in two decades at an elevation of 7,600 feet. Gregg Stults, a wheat farmer near Wray, shared that the heat persisted into autumn, with several evenings in a recent month seeing temperatures above 90 degrees at 9 o'clock at night.
The number of 90-degree days during the water year also underscored the unusual heat. Boulder experienced 57 such days, significantly more than its average of 33 for the last 30 years. Lamar saw 97 days over 90 degrees, compared to its longer-term average of 73, and Steamboat Springs recorded 29 days, far exceeding its 1991-2020 average of six.
Precipitation across most of Colorado remained below average throughout the water year. April precipitation, crucial for crops and grazing ranges on the Eastern Plains, was notably low. Coupled with much above-average temperatures, this led to rapid drought development and severe impacts on agricultural lands. Groundwater extraction likely increased, impacting aquifers in the San Luis Valley and the Republican River Basin. Parts of Garfield and Pitkin counties have experienced 15 consecutive months of drought by one measure.
The extreme conditions also affected wildlife. In Aspen, Greg Poschman, a resident, attributed the unusual prevalence of bears on city streets to a near-total absence of food at higher elevations, with shriveled service berries and non-existent chokecherries forcing bears into town. The Roaring Fork River, by name implying vigor, saw its streamflow reduced to 7 cubic feet per second, with water temperatures reaching 70 degrees.
The state's snowpack was the lowest on record, peaking at 51% of average and melting approximately a month early due to an unprecedented March heat wave. Jay Fetcher, a rancher along the Elk River northwest of Steamboat Springs, recorded snow disappearing from his hay meadow by March 2, shattering the previous record of March 24 set only a few years prior. By one broad measure, the Palmer Drought Severity Index, the past year was the worst on record.
Russ Schumacher, the Colorado state climatologist and a faculty member in CSU’s department of atmospheric science, emphasized that 2026 is not necessarily the new normal, and this past year will likely stand out as extreme in another 10 to 20 years. However, he cautioned that the chances for extremely warm years are increasing as warming continues. Brad Udall, of Colorado State University, warned that years like this will not only become common but will also worsen. While some hope for abundant snows this coming winter from El Niño, past El Niño winters have often brought minimal precipitation.
