• Black Diamond - Twilight Bivy - Wasabi
    Black Diamond - Twilight Bivy - Side
  • Black Diamond - Twilight Bivy - Wasabi
  • Black Diamond - Twilight Bivy - Side
Black Diamond - Twilight BivyView Larger Image

Black Diamond Twilight Bivy

30% Off
$104.97 $149.95

Item #BLD1190



Tech Specs

NanoShield (silicone-treated, single-layer proprietary fabric)
82 x 33 in
Floor Space:
18.75 sq ft
mesh panel
Packed Size:
3 x 5 in
Trail Weight:
10.7 oz
Recommended Use:
ultralight backpacking
Manufacturer Warranty:
1 year

Protection for ultralight trips and an insurance policy for unplanned nights out.

When the wind and rain start to blow during your solo mission, reach into your pack, and pull out the super-compact and lightweight Black Diamond Twilight Bivy. The water-resistant NanoShield fabric seals out the elements as it surrounds your sleeping bag and breathes better than virtually any water-phobic fabric on the market. A zippered opening at the shoulders provides easy access and lets you sit up to stretch your aching muscles in the middle of the night.

  • Single-wall bivy design saves weight by eliminating the need for a tent canopy, poles, and fly; ideal for year-round minimalist applications
  • Breathable, abrasion-resistant, and highly packable NanoShield fabric features a silicone NanoCell coating to protect against rain, snow, and wind
  • No poles to save weight for minimalist excursions
  • Mesh panel over face keeps out bugs, helps cut down on condensation buildup, and is removable
  • Small size fits easily into a backpack, bike pack, or haul bag
  • Optional footprint sold separately
  • Reviews
  • Q & A

Good winter bivy bag

  • Familiarity: I've used it several times

First thing I did was cut out the pointless mosquito netting. Should tell you all you need to know about where this review is coming from.

This is a good lightweight bag for alpine climbing. It is not suitable for summer rock routes where the material is simply too skimpy to serve any use. It will not keep you dry if it rains. I spent a night under constant spindrift though and stayed perfectly dry where without the bivy sack I'd have been soaked. Word of caution though: you want a narrow sleeping pad. I was using the large version of the Thermarest Neoair XTherm and it stretched out this bivy sack enough to go taught over my chest. I couldn't turn over, which was a problem, because it meant I took all that spindrift to the face. Swapped it out for a narrower sleeping pad though and now it's all good.

Why they'd put mosquito netting in a non-waterproof bivy sack though is beyond me.

Good winter bivy bag

Hey Bogdan! WOW that picture in incredible, thank you for sharing that and for writing such a helpful review!

Could be great...

  • Familiarity: I've used it several times

The price point of this bivy is nice, and in most conditions does the job.

Pros: Packs very small and light. Price.

Cons: The zipper on mine lost some teeth after only a few uses. Spent an hour in light rain and my bag started getting water after about 15 minutes. I would expect at least an hour of rain resistance. I also wish the opening was an inch or two wider, getting in and out was a yoga workout.

If you are looking to try a bivy get this and see if you like it. If you bivy a few times a year on a regular basis consider something else...

Fills its niche perfectly

  • Familiarity: I've used it several times

Like any bivy, you're only going to get so much protection in extreme conditions. This is not the sack to take in nasty weather, but it easily handles light rain, is a good supplement for floorless tents and tarps, dries quickly in the sun, and its lightweight and compactness make it a great minimalist option for all terrains.

It's certainly a no frills bivy, and you'll want to elevate your upper body slightly in rain to keep water from drifting into the opening. Those who can't stand fabric across their face will find hiding from bugs or rain uncomfortable, but in fair weather this is as good as it gets. I find the fabric a little slick, meaning it'll walk you around a bit if you're an active sleeper, but condensation is on par with other offerings and the gram counters will appreciate what it delivers for the weight. This is now my go-to 3 season and fair weather sack.

Fills its niche perfectly

Does what it's meant to and nothing more

  • Familiarity: I've put it through the wringer

There's nothing really more simple than this bivvy. The opening is pretty tiny, which makes it a little hard to get comfortable - think about getting out and in of it in the middle of the night to answer the call. It IS super-lightweight, though and will do its exact purpose well. I've done month+ trips with this bivvy, along with a tarp and it handled everything I needed. Its spacious enough for a regular sleeping bag and a 3/4 sized pad to fit inside. If you're sleeping on an abrasive surface, I would suggest some sort of ground cloth as well. Wash it with Tech Wash or similar once a year and put a water proof treatment on it, and it's good to go.

Does what it's meant to and nothing more

My first bivy!

  • Familiarity: I've used it several times

I have use this bivy two times, and all I can say is that I can't wait to use it again. This bivy is lightweight and versatile, the cons is that isn'€™t very breathable, it condensate if you close it. The second time I used it didn'€™t happened, maybe because I didn'€™t closed completely or I slept on a higher elevation, were the air was dryer and the wind stronger.
But overall I recommended!

My first bivy!

is this Bivy waterproof?


At most this is water-resistant. It has the Nano-Shield treatment which is a silicone treatment.

Shoot me an email anytime you have questions!

Jared D.

Expert Gearhead



It works great in snow. I've never had it in a hard rain. being in any bivy in the rain is a miserable experience. Bring a tarp!

Unanswered Question

Is the mosquito net fine enough so that it works with midges too (the ones in Scotland)? I am looking for a light and small bivy for a bikepacking tour around Scotland.

Unanswered Question

Hi, I am wondering how I can roll up and...

Hi, I am wondering how I can roll up and fix the mosquito net in the BD Twilight Bivy when the bivy is closed.

Closing the net when the bivy is open is easy.

Rolling down and fixing the net with openbivy cab be done by using the loop and the little cord with the tanka.

Now, this loop/cord method does not work with closed bivy.

Do I always have to close net and bivy or can I roll up the net also when the bivy is closed? Thanks a lot for your answers.


I'm 6'2", 175 pounds. Is this bivy will...

I'm 6'2", 175 pounds. Is this bivy will fit me or I have to find another model? (any tought on other fully enclosed bivy that packs small as the twilight?)

Best Answer

The bivy is 6'10" long. With a long-sized bag, you should just fit inside.

im wondering if you have to seam seal this...

im wondering if you have to seam seal this with mcnetts seam grip like all the other silnylon offerings from BD?

It's a decent idea. You don't really have seams that are exposed to the direct force of rain like you would on a tent, but it can still seep in.

I bought the BD Spotlight bivy, nearly the same as this one, and I did have to seam seal it myself

if i understand correctly, this bivy has...

if i understand correctly, this bivy has one zipper running across the shoulders and thats it? What about venting down by the feet, easy entry, etc...

That's it. The fabric is very breathable, so no venting. The zipper is wide enough that you should be able to side in easily, unless you're wide.

Worst Night Out In A Long Time...

    After reading some mixed reviews on this bivy, I decided to give it a shot in an effort to lighten up my kit by about a pound. I was hoping to use it in moderate weather in the alpine where little to no precipitation would be seen. As the weather forecast was looking beautiful, I took it out this weekend for a test run atop a snowy ridge in the Cascades. Ideal conditions, clear skys, light wind, no snow, and this thing managed to sucked hard. I woke up three hours into the night to find the inside of the bivy completely soaked. A few hours later and my bag was soaked through and no longer providing me warmth. I have no idea how the product description can claim bit of breathability, as this bivy was about as breathable as a trash bag. Quite a long and cold night from that point on. A point to note; I slept with the hood open and my face out into the air all night long. My breath did not contribute to the condensation in the bag. The seams were also sealed with Seamgrip prior to spending a night in it.
    It was a bummer that this bivy didn't work out as I would have liked. I don't recommend this, or any Black Diamond bivy made of this material to anyone who would use it in an alpine environment. I'm glad I tested it on a mellow climb where the only repercussions were a shiver bivy and a lack of sleep. Anything bigger and things could have been worse.
    Do yourself a favor and steer clear of BD bivys.

    What have I learned from this review? Do not seal the seams of this bivvy. I sleep great in it in my 0 degree down bag.

    I'm new to this bivy idea... I've got a...

    I'm new to this bivy idea... I've got a WM Ultralite with 38" in the foot. Would that somehow fit inside this bivy? or should I look for one with more foot-room?

    It will fit...but room & bivy? (;

    How durable is this super light fabric? ...

    How durable is this super light fabric? I plan on using it quite often and don't want to buy a new one every couple years. How long will this bivy last?

    It is pretty fragile but the question of how long it will last is really subjective. If you are bivying on flat ground with no rocks or sharp pointy objects like sticks or on a portaledge it will last much longer than on icy ledges and granite cliffs.

    my main concern with a bivy is not in...

    my main concern with a bivy is not in keeping me dry in a 10 hour downpour. Rather it is to protect my down bag from splashes coming off a tarp/open floor shelter/ snowcave/ dew, etc.

    Problem is that I am a warm sleeper and my down bag is notorious for not breathing very well by itself. Therefore, i need to make sure the bivy sack I buy can breath really well. Does anyone know how this BD fabric compares to eVEnt or membrain? I am desperately trying to avoid the dreaded bivy condensation

    The BD fabric is highly breathable and you should not encounter any problems. If you have issues you can always return for a full refund

    The NanoShield fabric is significantly more breathable than eVent or Membrain.



    Ridge camp in Juneau AK

    Ridge camp in Juneau AK

    Is a footprint recommened?

    Is a footprint recommened?

    Nope, you're fine. Silnylon bottom fabric is completely waterproof.

    Whats the ventailation like? The inside...

    Whats the ventailation like? The inside tag said theres a suffication danger.

    It's made out of a crazy breathable silicon impregnated nylon. Basically they coat each individual fibre with silicon which gives a high water resistance while still allowing airflow. It's not as breathable as no fabric, but it's about as good as it's going to get as far as single wall bivvy fabrics go.

    Great Ultralight Bivy

      I use this bivy for backpacking and car camping. It is extremely compact if compressed a little it's a little bigger than a baseball, light, and breathable. It's not entirely waterproof but will keep you dry from light rain and morning dew, it does a good job keeping the wind off as well. I usually pair it with a light weight tarp in heavier rain and snow. It's pretty spacious, I'm 5'8, 165lbs and I have tons of space to move around and enough room for my boots and clothes if needed. There are loops that you can easily tie up the cloth around the face area to keep it elevated but the material is so light I barely notice it when I sleep. Over this is an awesome bivy.

      Great Ultralight Bivy