Ski season is here, but for now, the eastern half of the U.S. digs out from winter stormsThe snow season has gotten off to a slow start in the western US.
There was snow cover much below normal in most of the West on December 1, 2025. Denver didn't experience its first significant snowfall until November 29th, more than a month later than normal, and last recorded date of first snow.
But a late start to the snow season isn't necessarily a reason to worry about the upcoming season.
Adrienne Marshall hydrologist in Colorado which examines how snowfall is changing across the West, explains what forecasters are watching and how rising temperatures are affecting the future of the West's favorite snow.
What are weather forecasters paying attention to now?
It's still early in the snow season, so forecasts are very uncertain. A late first snow does not necessarily mean a year with little snow.
But there are some patterns that we know influence the snowfall that forecasters monitor.
For example, the National Oceanic and Atmospheric Administration La Niña conditions forecast for this winterIt is possible to switch to neutral in the middle of the process. La Niña suggests cooler than normal sea surface temperatures in the Pacific Ocean along the equator west of South America. Cooler ocean temperatures in this region may affect weather conditions throughout the US, but several other factors may do the same.
La Niña—and its opposite, El Niño—do not tell us for sure what will happen. Instead, they load the bones toward wetter or drier conditions, depending on where you are. La Niña is usually associated with cooler and wetter conditions in the Pacific Northwest and slightly warmer and drier conditions in the US Southwest, but not always.
When we look at snowfall impacts, La Niña generally means more snow in the Pacific Northwest and less in the Southwest, but again, there is a lot of variability.
Snow conditions are also highly dependent on individual storms, and are more random than the seasonal pattern indicated by La Niña.
If you look at NOAA Seasonal Mapsmuch of Colorado and Utah fall between the cooler, wetter weather in the north and the warmer, drier weather in the south expected for winter 2026. So the forecast calls for roughly equal chances of more or less snow than normal, as well as warmer or cooler weather at many major ski resorts.
How is climate change affecting snowfall in the West?
In the West, snow measurements date back a century, so we may see some trends.
Beginning in the 1920s, surveyors went into the mountains and measure snow cover in March and April each year. These entries suggest snowfall has decreased in much of the West. We also see evidence more melting in midwinter.
The amount of snow that falls depends on both temperature and precipitation. temperature rises
Over the past few years, research has revealed directly relate observed changes spring snow cover and anthropogenic climate change. Warmer temperatures have led to less snowfall, especially in the Southwest. The effect of warming on total precipitation is less clear, but the net effect in the western United States is a decrease in spring snowpack.
When we look at climate change projections for the western US in the coming years we see with a high degree of confidence that we will be able to expect less snow in warmer climates. In scenarios where the world produces more greenhouse gas emissions, this worse for snow season.
Should states be concerned about water supplies?
The forecast for this winter is not extreme at this time, so the impact on water supplies this year is a bit of a question mark.
Snow cover – how much snow is on the ground in March or April – sums up the snowfallwithout melting, for a year. Snow cover also affects water supplies for the rest of the year.
Western water infrastructure system was built with the idea that there would be a natural reservoir of snow in the mountains. California relies on snowpack about a third annual water supply.
However, an increase in temperature leads to early snow melt in some areas. Available evidence suggests that climate change is also expected to lead to more rain on snow events at high altitudes, which can cause snow to melt very quickly.
Both pose problems for water managers who want to store as much snowmelt runoff as possible in reservoirs so it is available throughout the summer, when states need it most for agriculture and to generate hydroelectric power to meet high electricity demand. If the snow melts prematurely, water managers will have to make difficult decisions as they also need to leave room in their reservoirs for flood control. Earlier snowmelt sometimes means they have to release stored water.
When we look at reservoir levels in the Colorado River Basin, especially the large reservoirs Lake Powell and Lake Mead, we see pattern of decline over time. They had very good snow and water years, as well as particularly difficult ones, including long drought. Long-term trends suggest an imbalance between supply and growing demand.
What else does snowfall affect, such as fire risk?
In years with little snow, snow cover disappears faster and the soil dries out earlier per year. Essentially, this leads to an increase in the duration of the summer dry period and more load on trees.
There is evidence that we tend to have large fire seasons after winters with little snow. This may be due to dryer fuel remaining in the forests, causing the ecosystem to burn. This is obviously a major problem in the West.
Snow is also important for many species of wildlife that are adapted to it. One example – wolverinean endangered species that requires deep snow for winter shelter.
What snow lessons should people learn from climate forecasts?
Overall, climate projections suggest our snowiest years will be less snow in expected warmer climateand this very little snow years they are expected to be more common.
But it is important to remember that climate forecasts scenario-based about how much greenhouse gases might be emitted in the future are not predictions of the future. World can still reduce emissions To create a less risky scenario. In fact, although the most ambitious emissions cuts look less likely, worst-case emissions scenarios are also less likely in accordance with current policy.
Understanding how choices can change climate projections can be empowering. Forecasts say: Here's what we'd expect if the world emits a lot of greenhouse gases, and here's what we'd expect if we emit less greenhouse gases, based on recent trends.
The choices we make will impact our future snow seasons and the climate as a whole.
This article has been republished from Talka nonprofit, independent news organization bringing you facts and trusted analysis to help you make sense of our complex world. He was written by: Adrienne Marshall, Colorado School of Mines
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Adrienne Marshall has received funding from the National Science Foundation, the National Oceanic and Atmospheric Administration, the US Geological Survey, the Colorado Department of Transportation, and the Alfred P. Sloan Foundation, and has previously received funding from the Carnegie Institution of Washington.
