A potentially historic El Niño is taking shape in the Pacific, and that has put ski areas across the northern Rockies under the microscope heading into winter.
Big Sky Resort decided to look backward before worrying about what might happen next.
The Montana resort recently analyzed more than three decades of snowfall records collected by Big Sky Ski Patrol to see how much its snowfall actually varies from season to season. The resort says the dataset goes back 34 seasons to 1991 and shows season long snowfall totals varying by about 16% from year to year.
That is significant because Big Sky sits in a part of the country where El Niño has historically tilted the odds toward less snow.
NOAA analyses of past El Niño winters show reduced snowfall across much of the northern Rockies, particularly during moderate to strong events. But those maps represent broad regional averages, not a snowfall prediction for an individual ski area.
Big Sky’s own data suggests the mountain may be less volatile than a regional El Niño map makes it appear.
“We’re not meteorologists, and nobody can predict exactly what winter will bring three months out. But we can tell you how Big Sky has behaved in winters past, and the answer is: steady.” -Big Sky
Big Sky Says Its Snowfall Tends to Stay Near Average
Big Sky currently lists an average annual snowfall of about 400 inches. The resort has 5,850 skiable acres stretching from the Mountain Village at 7,500 feet to the 11,166-foot summit of Lone Peak.
According to the resort’s analysis, its annual snowfall totals tend to stay relatively close to that long-term average instead of swinging dramatically between exceptionally snowy and exceptionally dry seasons.
Big Sky Snow Safety Assistant Director Chelan Babineau-Z put it this way:
“Our snowfall here generally trends toward average. When winters start slow, they tend to make up ground later, especially through the deep-winter months.”
Big Sky also points to the distribution of its snowfall through the season. Rather than depending on one exceptionally snowy month, the resort says snowfall is typically spread from early winter into spring.
That does not mean El Niño has no effect on Big Sky. It means a large-scale climate signal is only one factor determining how much snow ultimately falls on Lone Peak.
This El Niño Is Not a Typical One
The timing of Big Sky’s analysis is notable.
NOAA’s Climate Prediction Center said Sept. 10 that El Niño is strengthening and now has a greater than 90 percent chance of becoming a very strong event during fall and winter 2026-27. NOAA also puts the chance at 75 percent that the October through December period reaches a level that would exceed previous El Niño events in its record dating to 1950, based on the Relative Oceanic Niño Index.
Unofficial Networks covered NOAA’s latest El Niño update last week, including what an unusually strong event could mean for ski areas across North America.
The Climate Prediction Center’s latest seasonal outlook continues to show the broad hallmarks of an El Niño winter. NOAA favors wetter conditions across much of the southern and central United States, while parts of the interior Northwest have a modest tilt toward below-normal precipitation. Warmer-than-normal temperatures are also favored across portions of the northern United States later in the fall and winter.
Historical snowfall data provide another reason for northern Rockies skiers to watch the pattern closely. NOAA’s analysis of El Niño winters since 1959 shows that snowfall has generally been reduced across the northern Rockies and Pacific Northwest, with the signal becoming more pronounced in many locations during moderate-to-strong events.
Unofficial Networks’ broader 2026-27 winter snowfall outlook similarly identified Montana and the northern Rockies as one of the regions facing a less favorable large-scale El Niño signal.
A Regional Forecast Is Not a Big Sky Snowfall Forecast
There is an important distinction here.
NOAA is not forecasting a specific amount of snow for Big Sky. Seasonal outlooks deal in probabilities over large geographic areas, and they cannot tell skiers whether Lone Peak will receive 300 inches, 400 inches or 500 inches this winter.
Even NOAA cautions that a stronger El Niño does not guarantee that its typical effects will occur everywhere. The current setup also differs from previous exceptionally strong El Niño events in ways that could alter the expected pattern. The Climate Prediction Center noted this week that the Pacific Decadal Oscillation is currently negative, unlike during the major El Niño events of 1982-83, 1997-98 and 2015-16. NOAA says that difference could weaken typical El Nino impacts in some areas.
Big Sky’s analysis provides the other half of that picture.
The northern Rockies may enter the winter with a climatological headwind, but 34 seasons of local data suggest Big Sky’s snowfall has historically been comparatively consistent from one season to the next.
That is not a guarantee of a 400-inch winter. It is also not evidence that El Niño should be ignored.
It is a reminder that a map showing broad seasonal tendencies cannot capture everything happening on an 11,166-foot mountain.
Big Sky is scheduled to open for the 2026-27 season on Nov. 25.
For skiers trying to decide what a potentially historic El Niño means for Montana, the answer remains frustratingly familiar: the odds can shift, but the snow still has to fall.
