Bivy for solo backpacking in winter?

If your sleeping system is just barely warm enough for the temperature then sleeping in a tent is better especially if there are clear nights.

If you have lots of warmth, no tent and watch stars.

I have only been snow camping once, with the Sierra Club to learn how to camp in the snow and I did use a bivy and tarp.

Granted, this was in a snow grave or trench with a tarp pulled over the top to trap heat.

The bivy could be warmer for you in that it can help trap heat…maybe at 2.5 to 5 degrees F of warmth to your sleeping system.

This may be an advantange to you vs. the tent, which will only be a few degrees warmer than the temperatures outside.

My opinion is that a bivy is used with a tarp….the tarp to give you somme overhead protection from snow. (A frame pitch) This is assuming that you are camping out on the snow vs. building a snow shelter/trench, etc.

You can debate if the tarp will give you a micro climate of a few degrees of warmth vs. sleep out in the open.

Regarding the bivy….with all of the layers that you are wearing and using for your sleeping system, if the bivy is too small/constricting, it will reduce the loft of your clothing and sleeping bag, which will make you colder.

A wide bivy might be in order….either way, if you are using a bivy, make sure that you try it out at home to make sure you have plenty of room inside the bivy for you to side sleep, if you are a side sleeper, or to simply fit all of your worn clothing and sleeping bag in there without being compressed by the sides or top of the bivy bag.

The other thing to consider for your mental health….being in a bivy bag and under a tarp can be a problem if you are stuck in a snow storm for hours and hours.

A tent would give you the ability to sit up and move around where a bivy and tarp may not.

Also, I agree with the prior poster….your sleeping bag is on the edge of what you will need to stay warm. Consider renting a warmer sleeping bag from REI, if you have one near you. The 20F rating is just to keep you alive…not comfortable.

Hope this helps.

-Tony

I've had a bit of experience using both a Gore-Tex (OR Alpine) and a generic PU bivy (REI Minimalist) in all seasons.

First off, I like bivying, as there's something to be said for the simplicity of it. Less nice is that the bivy I prefer is quite expensive and still needs to be "setup" with a single pole.

In my experience, the bivy excels in temperatures just above freezing, where it breathes the best and the moisture is able to easily pass through the membrane. Once you go below freezing, you start to get condensation frost on the membrane instead, which doesn't pass through readily and sometimes melts onto your sleeping bag. I had a lot of this particularly around the head and foot area of my bivy.

Perhaps eVent would be significantly better, and it definitely is in my jacket and pants, but I never bothered to make the investment in an eVent bivy.

I do think bivying is a great way to camp, but I don't think it's a be-all end-all solution. It's definitely not always the most comfortable way to camp but it does mean you have shorter set-up and take-down times as well as a lighter, more compact sleep system.

There's winter and then there's *winter.* Are you talking 20 degree days or 20 degree nights?

Bill S.

One way that a bivy sack can be helpful is if you are sleeping in a snow cave or snow igloo. Snow shelters tend to be very well insulated against the outside cold temperatures, so if you get some human body heat going inside, often the inside snow surfaces will begin to melt. If this is well constructed, the melted snow will form at the ceiling and slowly migrate to the lower surfaces, and sometimes it will re-freeze there. However, your sleeping bag may be in the way. If your sleeping bag gets wet from the migrating moisture, it will lose its effectiveness in a hurry. However, it doesn't take too much of a bivy sack to keep this moisture off.

–B.G.–

Depending upon how harsh your winter conditions will be, if you are not planning to use a tent or tarp you should check out the Miles Gear Uber Bivy.

In temps that are well below the freezing point, such as you mention, I'd recommend using a Vapor Barrier Layer inside your bag, regardless of what type of shelter you plan to employ.