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I am searching for a sleeping bag that would allow me to comfortably sleep in the snow eventually at a significant altitude (2800 meters - 9000+ feet), but also (and likely most often) at lower altitudes (2000 meter or so). I plan to sleep mostly with no tent (by digging a hole in the ground and then covering it partially with a tarp, or by digging a cave; along with a bivi bag)

I really have no idea about what could be the good sleeping bag temp range to look into. I don't want to feel any cold at night, but at the same time I'd want to avoid any extra weight and bulk to carry if it's not necessary - perhaps to end up by sweating in a bag that's way too warm.

Any help from any actual alpine winter camper would be appreciated. Many thanks

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    No such thing as too warm at that temp and altitude!
    – user2766
    Nov 17, 2014 at 16:00
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    @Liam I am not completely on your side (see my answer) but I think it was Steve House who said: "Light and fast means cold and hungry."
    – Wills
    Nov 17, 2014 at 23:31
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    @Liam well, perhaps a Valandré Thor meant for extreme Hymalaian expeditions could be too heavy and big to carry - a bit "overkill", so to say. But I actually have no idea not having any winter alpine bivouac experience... yet.
    – Dakatine
    Nov 18, 2014 at 7:52
  • Edit: here's PHD voice on the subject which also confirms this for quality down: phdesigns.co.uk/cleaning-down-sleeping-bags-and-clothing
    – Dakatine
    Nov 20, 2014 at 14:00

2 Answers 2

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First of all, I will just spread some ideas. I never did a winter bivi by myself. Please don't blindly trust my words.

But... because I am interested in the idea and like to do something similar in future, I searched for some info which might help you (and me). Still I am looking forward for better answers (which are based on experience and real knowledge!).


There is such a thing as too warm. Weight. Size. Depending on your activity outdoors you shouldn't "simply" get the warmest sleeping bag. You might get really slow while climbing due to the heavy load and we all know the premiss: speed means safety.

It's not in extreme heights and winter isn't necessarily that cold in the Alps. Of course it's not the Himalayas, but we also shouldn't downplay the risks. I tried to get some information about temperatures. There has to be better and more detailed data, but this is a starter:

  • Temperatures for the Eastern Alps over the last years as an average over several summits in the asked height level

http://www.querschuesse.de/wp-content/uploads/2014/10/A423.jpg enter image description here

From the above links we can guess how cold it will be at night. But we can't say for sure. Tough to find some night temperatures (with statistics) but at least here is a

So you can observe the actual temperatures at night for some cold places in Switzerland.

More food to think about:

  • Which part of the Alps are you going to? South Alps are generally warmer due to Mediterranean influence, even at winter.
  • Will there be Foehn? Atmospheric inversion?
  • Check the weather even more detailed as you would in summer!
  • How do you generally feel in terms of coldness? Are you feeling cold easily?
  • The sleeping bag is just a part of the equipment. As important is the kind of bivi sack and mattress you are using.
  • You are going to sleep in underwear or fully dressed (related)?
  • How long do you plan to be outdoors? One night or five? Wet conditions on a multiday trip without having the possibility to get dry clothing is a major problem. Down suffers from this even more as synthetic fibre and even the second night could be really bad if you have to go in your damp-wet sleeping bag...
  • Will you use a vapour barrier liner for the sleeping bag (and maybe also socks)?

Also if you are going to dig a snow cave, please learn how to do it properly! Otherwise choking instead of the cold might be the biggest danger. If you have the conditions (you won't necessarily have enough snow to get a good cave) you could get a pretty warm place to sleep - around freezing point. Please read along: Using a tarp over the entrance of a snow cave, Best approach to camping in snow, How to set up a tent in deep snow

For bivi packs see e.g. Differences for bivi packs, for the bivi see Planned winter bivi.


I also found a topic in German where they discussed a similar question. He asks for nights down to -35°C which might occur but this is somehow extreme for the typical night in the Alps. I think -20°C is more likely. With your additional gear and clothing you most likely don't need a sleeping bag with comfort temperature of -20°C...

The guy in the link above ends up with following setup:

Therm-a-Rest Haven, 3/4- 14mm- Eva- mattress, Exped VBL-Liner

This is a bag with T_comfort=-1°C, T_limit=-6°C, T_extreme=-23°C which I personally wouldn't suggest. But he tested it with all his personal requirements and gear in around -20°C and was very happy with it.


This is a very good and complex question. I think there is no distinct answer like "you need a T_limit=-25°C bag for the Alps". There is so much to think of for preparing the trip and I would suggest to not just jump into a winter bivi in 2800m from zero experience, get there with incrementalism.

Again, I just tried to gather informations, this isn't a proper answer. I hope we get more useful replies soon!

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    Thank you very much for your insightful answer. Yes indeed everything matters and I already got a therm-a-rest xtherm mattress that should be among the warmest on the market. And yes I also thought about the bivy bag. But along the way, I stumbled across some bags (as the feathered friends) that have a waterproof and breathable surface, and that would remove the need for a separate bag, perhaps. Also, I found a site that would allow you to make your custom (and super expensive) bag, just to make the decision harder: phdesigns.co.uk
    – Dakatine
    Nov 18, 2014 at 7:59
  • Moreover, and off-topic, but I didn't found a way to message you privately, I've seen you're from Munich (lovely town BTW). I live in the opposite side of the Alps, that's Milan. And I think only a few people may be interested in doing this winter experience. Maybe we can just plan ahead and go together.
    – Dakatine
    Nov 18, 2014 at 8:05
  • @Dakatine I disagree that this is a narrow topic. The altitudes my have change, but there are chances for winter camping all across the northern hemisphere. Nov 18, 2014 at 15:50
  • Indeed. But what I am interested into right now is the alpine climate with its features (altitude, wind, temperature. Avalanche risk is another subject but very real)
    – Dakatine
    Nov 18, 2014 at 18:03
  • @Dakatine Yes there is no messaging system on SE network. When I am online (mostly in the evening) you can find me in the chat.
    – Wills
    Nov 18, 2014 at 18:47
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If you sleep only in a bivy bag direct on snow you need to have a sleeping bag with a good isolated pad for the temperature in the forecast at least.

If you sleep in a well build igloo the temperature is much warmer than the outside.

Snow is used because the air pockets trapped in it make it an insulator. On the outside, temperatures may be as low as −45 °C (−49 °F), but on the inside the temperature may range from −7 °C (19 °F) to 16 °C (61 °F) when warmed by body heat alone. - wiki

For a snow cave you can plan with this given temperature

The temperature inside a snow cave is usually 15 to 20 degrees warmer than outside, which can make the difference between life and death. The temperature in a well-constructed snow cave, relatively free of outside air incursion, typically hovers around 32 degrees Fahrenheit regardless of outside temperature. - The Seattle Times

From my personal experience I used a comfort -2 Celsius degree sleeping bag in a igloo/snow cave with a isolated sleeping pad and i was comfortable warm during the night. The temperature outside was down to -20 °C. And if you're still cold you could also wear long underwear or your down jacket/pants/socks like on some expeditions and wear also a hat/buff on your head. Then you can go with a cheaper and lighter sleeping bag. :)

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  • Thank you. Do you have an idea of what temperature was outside the cave? By the weather forecast, for instance.
    – Dakatine
    Nov 20, 2014 at 12:16
  • I had temperatures till -20 Celsius degrees. You don't like to realize that you need to go to toilet during the night ;)
    – ibex
    Nov 20, 2014 at 13:04

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