AVALANCHE ON THE ANNAPURNA BASE CAMP TREK:
An avalanche is triggered when an unstable mass of snow breaks away from a slope. Layers of snow build up on the side of a mountain to form a snowpack. Avalanches occur as layers in a snowpack slide off. According to National Geographic, “Melted snow that refreezes may cause a slick coating of ice to form on the surface of a layer. A new snowfall may not stick to this slippery layer, and it may slide off. During spring thaw, melted snow can seep through a snowpack, making the surface of a lower layer slippery. Added weight or vibration can easily send the top layers of a snowpack hurtling downhill.”
Annapurna is particularly prone to avalanches due to several geological and environmental factors. The steep slopes on Annapurna make it difficult for snow to remain stable. Also, the gullies in the Annapurna region funnel avalanches to the narrow valley and onto the trails. Substantial snowfall, which is common in Annapurna, can also trigger avalanches. If there has been a recent heavy snowfall there will be avalanche risk on the slopes. As a general rule, it is best to leave the snow-pack to stabilise for several days after a snowfall.
The deadliest avalanches on the Annapurna Base Camp route:
25 March, 2001: Four Australians including an 8-year-old girl were killed by an avalanche between Hinku Cave and Deurali. They were members of the support group of the all-Australian Everest expedition team and were on a warm-up hike to Annapurna Base Camp. This story was covered by CNN.
17 January, 2020: Again, in between Hinku Cave and Deurali, an avalanche triggered by heavy snowfall claimed the lives of four South Korean trekkers and 3 Nepali guides. This incident was covered by Al Jazeera. The bodies of several of the deceased were not recovered until several months after the incident.
Besides the above, there are fatalities on this route almost every year. This year, in late March 2025, an avalanche fatally struck a solo Chinese trekker. The incident occurred between Deurali and Macchapuchare Base Camp. While there is an alternate trail that is used early in the season to avoid the avalanche prone trail, the solo trekker was probably not aware of this route. Also, early this year in January, an avalanche struck another group of trekkers. They were reported as missing.
The riskiest section on the Annapurna Base Camp route:
As is obvious from the incidents above, risk for avalanches is highest on the section between Hinku Cave and Deurali. This is because the canyon here is narrow and any avalanche off of Hiunchuli will reach the trail. However, there is still a substantial risk for avalanches all the way up to Machhapuchare Base Camp after which the valley begins to widen. So one must be careful throughout from Hinku Cave to Macchapuchare Base Camp. Do note, beyond Deurali the locals have opened up an alternative trail that avoids the most dangerous sections. That said, there is still some risk even on this alternative route.
The most dangerous months of the year:
The Annapurna massif experiences substantial snowfall during the winter and pre-monsoon seasons. Heavy, wet snow can form unstable layers that collapse under their own weight. Hence Winter (January and February) is the most dangerous time to trek to the Annapurna Base Camp. It is best to avoid trekking during these months though quite a few trekkers do make the trek every year.
Spring (March through April) while not as dangerous still carries a degree of risk. Variations in temperature and snowfall create layers within the snow-pack. Weak layers can form beneath heavy snow, making the entire snow-pack prone to collapse. Temperature fluctuations between day and night can also lead to melting and refreezing, further weakening the snow’s structural integrity.
That said, there is some level of avalanche danger any time of the year. An unusual heavy snowfall in the winter or a freak snowstorm can also cause avalanches. In February 2019, heavy snowfall caused four tea-houses at Annapurna Base Camp to collapse. See Kathmandu Post article. There was so much snow on the trail that the route had to be closed for several months.
On 14 October 2014, a snowstorm dumped over 1.8 meters (almost 6 feet) of snow within 12 hours triggering several avalanches. This was the deadliest day in Nepal’s tourism history resulting in dozens of fatalities. This is evidence that such freak snowstorms can occur at any time of the year. October is usually regarded as the best time of the year for trekking in Nepal with minimal chances of snow. This disaster was preventable as Cyclone Hudhud had been predicted for many days. Forecasters had tracked the storm across India and north into Nepal. See BBC article.
How to minimize the risk of avalanche:
Every year, thousands of trekkers venture to the Annapurna Base Camp. Just because the Annapurna trail is avalanche prone does not mean you should avoid trekking there. After all, the Annapurna Base Camp trek is one of the most beautiful treks in Nepal. Below are some precautions one should take to minimize the risk of an avalanche:
Knowledge –
Avalanches on this route usually occur on the same sections of the trail. Knowing where avalanches occur will allow a trekker to be extra vigilant while on those sections. Experienced guides will know this and will constantly consult locals and other trekkers on the current conditions and will have a good idea of the risk. The general rule of thumb is to avoid trekking (stay put) when there has been a recent snow fall of more than 12 inches as the next 24 hours is considered very risky. Access to reliable weather reports is also invaluable. We at Crystal Mountain Treks will buy weather reports when we have groups trekking to Annapurna Base Camp during the months of March and April. We dissuade trekkers during the months of January and February.
Avoid trekking alone –
It is a bad idea to trek alone. You will not know which sections are avalanche prone. And no one will know if anything has happened to you. So even if you decide not to hire a guide, you should at the very least always team up with other trekkers/trekking groups as you trek from Hinku cave to Machapuchare Base Camp.
Start early –
It is best to cross the most dangerous sections early in the morning when the snow-pack is still firm. Later in the day, with the sun hitting the slopes, chances of an avalanche increases. Our standard Annapurna Base Camp Trek itinerary stops at Himalaya (starting at Bamboo) and, on the next day, crosses Hinku cave and Deurali early in the morning. Most companies will not stop at Himalaya but instead hike directly from Bamboo to Machhapuchare Base Camp crossing these sections later in the day.
Some videos of avalanches on the Annapurna Base Camp trail:
The above video was taken near Dobhan after an avalanche and was taken in March 2025. This is not an area known for avalanches. And was surprising to see.
The above video is of the trail after an avalanche between Hinku Cave and Deurali and was taken in March 2025. This is the most notorious section for avalanches.
The above avalanche occurred past Bagar enroute to Machapuchare Base Camp. This video was taken in March 2025. Below is the drone footage of the avalanche in the same area and was shot in 2024.
The video below is of the trail near Macchapuchare Base Camp after an avalanche
Avalanches can occur even in late May and June as the video below shows.
