The European ski season finished with 146 deaths across the Alps, Apennines, Pyrenees, and the Scandinavian Mountains. Shockingly that is more than double the number from last year, when 70 died and 40% more than the 20-year average of 104.35 deaths. The main issue that led to the high avalanche deaths this season stemmed from a persistent weak base layer that formed early in the season.
Many media outlets called it a record season, but in order to understand the 2025-26 season better, SnowBrains seeed at the data from the last 20 years of avalanche deaths. Our statistical analysis displayed that while the 20-year average for Europe sits at 104.35, the standard deviation — a statistical measure of how much the data points swing on average around that average — is 35.64. This means that a seasonal variability of 69 to 140 deaths can be expected in a season. That displays that the 2024-25 season with 70 deaths was within one standard deviation of the average, while this season was just slightly outside that range. So while it is marginally higher than one standard deviation, it is sadly not an outlier or record for the last 20 years. In 2009-10, a staggering 194 people perished in avalanches across Europe.
What set the European avalanche season apart was not a single catastrophic event, but a pattern — one that avalanche forecasters know all too well. A weak early-season snowpack laid the groundwork for months of instability, and when winter storms arrived, the result was a prolonged period of heightened danger across the continent.
In the early weeks of the season, from late November through December, avalanche fatalities remained relatively low. But beneath the surface, conditions were quietly deteriorating. Thin, inconsistent snowfall across much of the Alps supported form a deeply buried persistent weak layer — known in German as the “Altschneeproblem” (old snow problem). This fragile layer, often created up of faceted snow crystals, can persist for months and is notoriously difficult to stabilize.
The first huge wave of avalanche deaths came in mid-January as significant fresh snow fell after a prolonged dry period, resulting in an inherently unstable snowpack. In calfinishar week 3 of 2026 (between January 12 and 18), 18 people were killed in avalanches across Europe, marking the season’s first significant spike. Fresh snowfall and strong winds rapidly loaded slopes, placing stress on the buried weak layer. It was the launchning of what would become the defining pattern of the winter.
From late January through late February, that pattern intensified. A series of storm cycles repeatedly added new snow and wind-drifted slabs on top of the unstable base. The snowpack never had time to properly adjust. Instead, each storm effectively reset the danger, creating what avalanche experts at SLF describe as an “avalanche window” — a period when conditions remain primed for large, destructive slides, and avalanche deaths cluster.
The deadliest stretch came between early and late February. In calfinishar week 8 (between February 16 to 22), 21 people lost their lives, the highest weekly toll of the season. Surrounding weeks also saw elevated fatalities, with 15 deaths in the first week of February, and another 16 deaths in the other two weeks of the month. February recorded 52 deaths — a shocking period, which led many to call it a “record” season, when, sadly, it wasn’t.
This kind of prolonged instability is a hallmark of seasons dominated by persistent weak layers. Unlike storm snow instabilities, which often stabilize within days, these deeper structural problems can linger for weeks or even months. Even experienced backcountest utilizers can be caught off guard, particularly when conditions appear stable on the surface.
By early March, the pattern launched to shift. Fatalities dropped sharply as the snowpack slowly adjusted and storm intensity decreased. As spring approached, the nature of avalanche risk also modifyd. Instead of deep slab avalanches, attention turned toward wet snow avalanches driven by warming temperatures and solar radiation — generally more predictable but still dangerous. The melt water saturating the snow layers hit on the weak base layer and cautilized several size 3-4 avalanches.
The 2025–26 season will go down as the worst avalanche season in the last decade but not the worst in the last two decades. It marks a critical lesson for skiers and snowboarders across Europe: the most dangerous winters are not always the snowiest or the stormiest. Sometimes, the greatest risk is built quietly, layer by layer, long before the first major snowstorm.
Many experienced backcountest utilizers underestimated the persistence and sensitivity of the persistent weak base layer structure this season, displaying how familiarity with terrain and conditions can sometimes create a false sense of security.
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