November 2025 Summary

Colorado’s snow season got off to a slow start in November 2025. During this dry stretch, any leftover October snow either melted away on sunny slopes or broke down into weak basal facets near the ground on high elevation, north-facing terrain. For much of the month, below-normal snowfall and above-average temperatures prevailed across the state.

Figure: Colorado statewide SWE (Nov. 2025). 

Late November finally brought a series of modest storms that blanketed parts of the state with much-needed snowfall. During the last week of November, 95 avalanches were reported across Colorado compared to just seven from November 17 - 22. Most were small, but the uptick showed the snowpack was starting to form thicker, more connected layers, and the hazard was building.

Statewide avalanche activity during November 2025:

• 95 avalanches recorded across the state
• 4 avalanches size D2
• 8 avalanches size D1.5
• 83 avalanches size D1
• 10 human-triggered avalanches

The following is a summary of snowpack and avalanche conditions from November 1 through November 30, 2025, by region.

Northern Mountains

The Northern Mountains remained mostly dry through the first few weeks of November. Only isolated patches of old snow from early fall lingered through the prolonged dry spell. These patches were mainly confined to upper-elevation, shady slopes near ridgelines facing north through northeast. In the last week of November, a few small storms delivered anywhere from a couple of inches up to 18 inches of snow in the most favored locations. This new snowfall was the first significant load on the fragile early-season base.

A handful of small avalanches were reported as these late-November storms rolled through, including the Northern Mountains’ first human-triggered avalanche of the season near Loveland Pass on November 29. Fortunately, these early slides were minor, and no one was caught. Avalanche danger stayed generally LOW for most of November, but started to creep upward by the end of the month as new snow stacked up on underlying weak layers.

Central Mountains

The Central Mountains also experienced a dry November, with a thin and generally stable snow cover initially. By mid-month, periodic snowfall began to slowly build the snowpack, especially on higher north, northeast, and east-facing slopes. The on-and-off storms and clear cold nights allowed layers of faceted (“sugar snow”) to develop on shady upper-elevation terrain.

Starting on November 28, a one-two punch of storms brought a noticeable uptick in avalanche activity across the Central Mountains. The Elk Mountains and West Elk Mountains around Aspen and Crested Butte saw a rash of small avalanches during this period. Observers reported 55 natural and human-triggered slides, mostly shallow soft slabs breaking on the weak layers beneath. While most of these avalanches were small and did not run very far, the sheer number was a clear indication of our very weak snowpack. By the end of the month, even a small amount of new snow was enough to produce cracking, collapsing, and small avalanches in the Central Mountains.

Southern Mountains

While still below average, the Southern Mountains received the most early-season snowfall in Colorado. Snow began accumulating in mid-November and continued to stack up through the end of the month, especially around Silverton, Red Mountain Pass, and Telluride. As a result, these areas developed a deeper snowpack than the rest of the state, but that came with mounting avalanche concerns.

By late November, the northwestern San Juan Mountains had developed a Persistent Slab avalanche problem. Each round of new snow and wind built thicker slabs on top of older weak layers, and conditions became steadily more dangerous. By November 30, multiple avalanches were reported in this area, including both natural and human-triggered slides. Some were large enough to bury or injure a person, underscoring how quickly the hazard had ramped up as storms added weight to a fragile early-season snowpack.

Conclusion 

The long dry spells of early November allowed weak, faceted snow and crusts to form, followed by late-November storms (beginning around Nov. 28) that added cohesive slabs on top of that fragile base. This is a classic setup for a Persistent Slab avalanche problem, where avalanches can break deeper and wider once triggered.  

November 2025 ended with a fragile foundation statewide and growing hazard in the zones that finally picked up snow. That combination that can keep avalanches in play even during otherwise quiet weather.