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Long-term statistics

The SLF has been collecting comprehensive data on all the avalanche accidents that have occurred in Switzerland since the winter of 1936/37. These data are compiled and analysed in the annual accident reports published by the SLF (German only). More than 100 avalanche accidents a year involving people are registered with the SLF.

Avalanche victims since 1936

The annual average number of fatalities over the entire period is 25 (Fig. 1). A more detailed overview can be found here.

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Figure 1:Avalanche fatalities in Switzerland since 1936/37. The graph illustrates the fall in the number of fatalities in buildings and on transportation routes. It also shows the averages for the last 80 years (25; black broken line) and 20 years (23; black solid line). During the last 20 years, more than 90% of the avalanche victims lost their lives in open terrain (download graph as PDF).

Spatial distribution of fatal accidents during the last twenty years

More than 90% of the fatal avalanche accidents during the last twenty years occurred in uncontrolled terrain, like for example during off-piste skiing and snowboarding or during backcountry touring on ski or snowshoes. As can be seen in Figure 2, a particularly large number of accidents occurred in the cantons of Valais and Grisons. Why are there so many accidents in these areas?

A zoomable map can be found here.

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Fig. 2: Regional distribution of the fatal avalanche accidents in Switzerland (20 years). For each of the more than 120 subregions, which are the basis for the regionalization of the avalanche bulletin, the number of fatal accidents was counted. The larger a symbol, the more accidents occurred in this region (map as PDF).

Avalanche accidents are life-threatening events!

According to statistics, only a little more than one in two people who are completely buried by an avalanche (head in the snow) survive. The most common cause of death among those who are completely buried is asphyxiation because the person often has no air supply or has access to only a small pocket of air. The chances of a person surviving a complete burial therefore reduce significantly after just 15 minutes (Fig. 3). For this reason, companions have a crucial role to play in quickly locating and freeing the person who is buried.

Life is also endangered if a person is swept along by an avalanche, even if the victim is not completely buried: at least one in seven fatalities occurs as a consequence of serious injury.

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Figure 3: Survival curve showing the proportion of victims surviving complete burial in open terrain (backcountry, off-piste) from 2005/06 until 2012/13. During this period The probability of a person surviving complete burial stood at a little more than 50% (download graph as PDF). For details refer to Procter et al., 2016.

Fatalities per danger level

According to long-term average figures, most fatal accidents occur when danger level 3 (considerable) applies (Fig. 4).

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Figure 4: Avalanche victims per danger level for persons caught while engaging in backcountry or off-piste activities, or in buildings or on transportation routes (accidents between 1997/98 and 2015/16, download graph as PDF).


Additional up-to-date assessments of avalanche accidents that have occurred in open terrain are available here.