10 Best Winter Sleeping Bags

10 Best Winter Sleeping Bags for Backpacking
The most important attributes of a sleeping bag for winter camping and backpacking are high-value insulation, compressibility, low weight, and ample interior space, so you have ample room to store gear and water in your sleeping bag, so it doesn’t freeze overnight. Cost is also a factor, although a good winter sleeping bag will last fifteen years or more if maintained and stored properly. For winter backpacking and other mobile pursuits such as backcountry skiing and ski mountaineering, we recommend you get a down-insulated winter sleeping bag because it packs much smaller and is much lighter weight.

We think the best bang for your buck is a 0-degree sleeping bag since you can boost its warmth with a low-cost liner if you need to sleep in colder temperatures than that. Most people avoid winter camping and backpacking when temperatures dip below zero anyway since it’s just not that fun.

Here are our top 10 recommended down winter sleeping bags for cold weather camping and backpacking. For more information and answer to common questions, see our evaluation criteria and buying advice below.

Make / ModelPriceDown Fill PowerWeightDown Fill Weight
Marmot Lithium 0$4998002 lbs 9.5 oz27.8 oz
The North Face Inferno 0$5198002 lbs 14 oz29.3 oz
NEMO Sonic 0$5008003 lbs25 oz
Therm-a-Rest Oberon 0$4908002 lbs 8 oz28 oz
Western Mountaineering Kodiak 0$6758502 lbs 12 oz30 oz
Feathered Friends Snowbunting EX 0$6199002 lbs 13 oz25.3 oz
Mountain Hardwear Phantom 0$6208502 lbs 10.630 oz
Sierra Designs Nitro UL 0$4208002 lbs 8 oz26 oz
Feathered Friends Ibis EX 0$6509003 lbs 1 oz28.5 oz
Big Agnes Star Fire UL 0$5808502 lbs 14 oz31 oz

1. Marmot Lithium Sleeping Bag

Marmot Lithium 0
The Marmot Lithium is a feature-rich mummy-style sleeping bag insulated with 800 fill power water-resistant goose down. It has a full-length two-way zipper with a draft tube and snag guard, so you can vent the bottom by your feet or anywhere you’re too warm. The Lithium has an adjustable, double-sided draft collar that runs over your chest and neck and behind your back to seal in your warmth. A second 1/4 length zipper on the other side provides additional ventilation and increases the bag’s range of use. Unisex.

Check the latest price at:
Backcountry | Moosejaw | Amazon

2. The North Face Inferno 0 Sleeping Bag

North face Inferno 0
The North Face Inferno 0 is a mummy-style sleeping bag insulated with 800 fill power goose down. It has a 1/2 length center zipper that makes it easy to get in and out of the bag or sit up in a tent while preventing zipper snags. A wrap-around draft collar and overlapping down baffles under the zipper seal in warmth, while trapezoidal side baffles prevent downshift from the top of the bag to the bottom. An internal pocket is provided for storing headlamp, a glasses case, electronics, and personal items, which is super useful in the confines of a winter bag. Unisex.

Check the latest price at:
The North Face | REI

3. NEMO Sonic 0 Down Sleeping Bag

NEMO Sonic 0 Sleeping Bag
The NEMO Sonic 0 is a mummy-style sleeping bag insulated with 800 fill power water-resistant down. It has a highly adjustable draft collar that encircles your neck and shoulders as well as a zipper draft tube to seal in warmth. The Sonic 0 has innovative Thermo-Gills (see picture) that let you release up to 20 degrees of warmth so you can regulate your temperature without cracking open the zipper and introducing cold drafts. Unisex. Read our review. 

Check the latest price at:
NEMOREI | Amazon

4. Therm-a-Rest Oberon 0 Sleeping Bag

Thermarest Oberon 0 Sleeping Bag
The Therm-a-Rest Oberon 0 is an 800 fill power water-resistant goose down sleeping bag that has zoned insulation, with 60% of the goose down positioned on top of the bag and 40% underneath to maximize its weight-to-warmth performance. Special sleeping pad straps keep you on your insulated sleeping pad at night so you can fully exploit its insulating power. Heat-trapping draft collars, full-length zipper draft tubes, a snag-free zipper, cinchable hood, and an external zip pocket, are engineered for optimal performance in cold and damp conditions. Unisex.

Check the latest price at:
Therm-a-Rest | Backcountry | Amazon

5. Western Mountaineering Kodiak 0 Down Sleeping Bag

Western Mountaineering Kodiak 0
The Western Mountaineering Kodiak 0 is a spacious mummy sleeping bag insulated with 850 fill power goose down. Designed for large folks up to 7′ in height (multiple lengths are available), it has 66″ of shoulder girth and 7″ of loft, to keep you comfortable and toasty. The Kodiak has a 3-dimensionally cut draft collar and zipper draft tube, as well as continuous baffles. These let you shake the down to where it’s needed most (for example to your chest or on top of your feet) and help you configure the insulating power to satisfy your individual needs. Unisex.

Check the latest price at:
Backcountry | Amazon

6. Feathered Friends Snowbunting EX 0 Sleeping Bag

Feathered Friends Snowbunting EX 0
The Feathered Friends Snowbunting Ex 0 is a mummy-shaped sleeping bag insulated with ultralight and ultra-warm 900 fill power goose down. It has a generously sized draft collar, draft tube, with an overlapping zipper-guard that prevents snags. The shell is made with  Pertex Shield EX water-resistant/breathable laminate, which is fully waterproof and windproof, making it good for use in snow caves and bivy sacks. The flexibility of continuous baffles allows the Snowbunting to also transition into the warmer months. Men’s. For women, see Feathered Friends Murre EX 0 Bag.

Check the latest price at:
Feathered Friends

7. Mountain Hardwear Phantom 0 Down Sleeping Bag

Mountain Hardwear Phantom 0 Sleeping Bag
Mountain Hardwear Phantom 0 Sleeping Bag
The Mountain Hardwear Phantom 0 is an 850 fill power sleeping bag made with ultralight materials to shed as much weight as possible while still providing superior performance. It uses a combination of multi-directional baffles to keep down from shifting when you get in and out of your bag frequently, along with a huge draft collar and draft tube to keep heat from escaping when you move around at night. The Phantom 0 has a special four-chamber hood that maintains even loft around your head for consistent warmth long with a two-way zipper that allows for easy ventilation when you want to blow off a little steam. Unisex.

Check the latest price at:
Mountain Hardwear | Backcountry | Amazon

8. Sierra Designs Nitro UL 0 Sleeping Bag

Sierra Designs Nitro UL 0

The Sierra Designs Nitro UL 0 is a low-cost 1/2 zip mummy-style sleeping bag insulated with 800 fill power water-resistant down. Weighing just 2 lbs 8 oz, it has a simple draft collar and zipper draft tube to seal in your body’s warmth. Plus, there’s a foot vent on the bottom of the bag that you can stick your feet out of if you’re too warm at night. Nothing fancy, but it gets the job done and the price is right. Read our Nitro UL 0 Review

Check the latest price at:
Sierra Designs | Amazon

9. Feathered Friends Ibis Ex 0 Down Sleeping Bag

Feathered Friends Ibis Ex 0
The Feathered Friends Ibis Ex is insulated with 900 fill power goose down, cut wide in the shoulders, that excels when you are pushing the comfort rating of bag and need space to wear a down jacket in the sleeping bag. It has a draft collar, draft zipper tube, and is made with a waterproof/breathable fabric enabling use with bivy sacks and in snow caves. Snap closures on the draft collar and zipper are easier to use than velcro fasteners, while continuous baffles let you position the down where you need it. Men’s. For women, see Feathered Friends Murre EX 0 Bag.

Check the latest price at:
Feathered Friends

10. Big Agnes Star Fire UL 0

Big Agnes Starfire UL 0
The Big Agnes Star Fire UL 0 is a highly efficient down mummy bag insulated with 850 fill power waterproof down. It has an oversized draft collar, a half zipper to save weight, a snag-free side zipper, an insulated draft tube, and Pertex Quantum shell to keep you toasty warm on cold nights. Body-mapped baffle construction optimizes thermal efficiency while the ergonomic foot-box construction provides more loft and warmth. Unisex.

Check the latest price at:
Backcountry | Moosejaw | Amazon

Winter Sleeping Bag Selection Advice

Mummy Sleeping Bag or Quilt?

A mummy sleeping bag is warmer and more comfortable than an ultralight down quilt under 20 degrees Fahrenheit. While quilts are popular for warm weather use, mummy bags are far less drafty when the mercury drops below 20 degrees. They also provide a warm overnight space where you can keep water, filters, and footwear overnight to prevent them from freezing. This is harder to do with an ultralight quilt, which is usually shorter and sized narrow to save weight. Sleeping in temperatures below freezing definitely changes your behavior and requires a different skillset and gear list than regular three-season camping or backpacking in warmer weather.

Down vs. Synthetic Insulation

Down insulation is more compressible and warmer by weight than synthetic insulation. How much warmer? The best synthetic insulation is only equivalent to 600 fill power down. What about moisture accumulation inside the bag? If you’re just going out for one night or a few nights in zero-degree weather, it’s unlikely that you’ll perspire enough to significantly reduce the insulation value of a down bag. It’s a very different story if you’re on an expedition where you’re sleeping out in -40 degree weather every night for weeks on end. Even then, most mountaineering guides and explorers still opt for down-filled sleeping bags over synthetic ones because they’re warmer, pack up much smaller, and are much lighter weight to carry. You can also dry out a sleeping bag during a trip in the sun to rid of it any extra moisture. People do it all the time.

Waterproof Down vs Non-Waterproof Down

There’s no such thing as waterproof down. While so-called down waterproofing treatments allow down to dry faster if it gets damp from perspiration, most premium sleeping bag makers won’t use it because it reduces the perceived insulation value of 800, 850, 900, ad 950 fill power goose down.

Temperature Rating

What is the best sleeping bag temperature rating to get for winter backpacking? While there are bound to be regional differences, a zero-degree sleeping bag is usually a good baseline temperature to aim for because you can easily make it warmer by 20 degrees by wearing insulated clothes or by using a sleeping bag liner, which can save you a chunk of money. A zero-degree bag can also be used in warmer temps up to about 20-30 degrees by cracking open the zipper or loosening up the hood and venting it if you’re too warm. The weight and packability of a zero-degree sleeping bag is also pretty reasonable compared to a  minus 20-degree bag and usually doesn’t require the purchase of a larger backpack to carry.

Best Type of Insulation

If you plan to do any winter backpacking, you’re going to want a down-insulated sleeping bag because it’s the warmest insulation available by weight. It compresses very well, making it very packable. Aim for down fill powers of 800, 850, or 900: the higher the better. Higher fill power down traps more warmth by weight than lower fill power down. People often wonder whether goose down is better than duck down. All down is graded the same way, in a species-independent manner. In other words 800 fill power goose down is as good as 800 fill power duck down, only more expensive because there’s a smaller supply.

Sleeping Bag Dimensions

It is common to sleep with boot liners or boots, water bottles, and other items, like water filters, that should not freeze overnight. This means you’ll want some extra space in a cold-weather sleeping bag to store the gear while still maintaining your personal comfort. In addition to added shoulder, hip, and foot width, some people get a longer sleeping bag so they can store gear below their feet. Winter nights are long and it pays to be comfortable, especially if you have to sleep with cold, damp boots and water bottles.


Most zero-degree winter sleeping bags are unisex. The one exception to this is Featured Friends which make seven women’s specific sleeping bags by our last count including 0, -10, and -25 degree winter sleeping bags.

Must-have Features

Winter sleeping bags should have a draft collar, zipper draft tubes, and snag-free zippers at a minimum. Partial length zippers, continuous baffles, vents, and even water-resistant down are all nice-to-haves, but you can get by without them to save on cost or because they’re not strictly necessary.

Draft Collar

Most winter sleeping bags have draft collars and I consider it a cold-weather essential. A draft collar is a tube of insulation that drapes over your chest and neck and seals in the bag’s warmth. Without it, the warm air inside the bag will rush out around your neck when you move around inside. The simplest draft collar is a down tube that covers the front of your chest. Higher-end bags add a second draft collar around the back of your shoulders and neck and provide additional controls, so you can tighten or loosen it.

Zipper Draft Tubes

Draft tubes are tubes of down that cover up the side zipper so your legs don’t come in contact with it (because it’s cold). They also prevent cold air from leaking into the bag through the needle holes that are created when sewing the zipper to the bag. Most winter bags have at least one zipper draft tube, although some have two, both top and bottom, that fall into place when you zipper up your bag.

Snag Free Zipper

Snag-free zippers prevent the side zipper’s teeth from tearing the shell fabric of your bag and spilling its insulation. The zipper is usually bordered by stiff fabric tape, to keep it away from the down baffles and prevent it from getting snagged on the bag’s outer shell.

Nice-to-have features

Water-Resistant Down

Water-resistant down is a nice to have, not a must-have in a winter sleeping bag. The truth is most people can keep their sleeping bags dry. If you notice moisture on the outside of your sleeping bag in the morning, it doesn’t mean that the down inside is wet. Simply drape it over your tent in the sun while you eat breakfast and it will dry in no time.

Continuous baffles

Continuous baffles usually run horizontally across a bag. They allow you to shake the down in the baffles and move it to a different location. For example, if you’re too warm, you could shake the down so it fell down the sides of the bag, rather than keep it on your chest. While continuous baffles let you customize the distribution of down for different needs, many people prefer baffles that keep the down in one place reliably and permanently. It’s one less thing to worry about.

Partial length zippers

Partial length zippers are often used as a weight-saving feature, however, they can reduce use across a wider temperature range by limiting your venting options.


Vents like NEMO’s Thermogills or Sierra Design’s Foot Vent can increase the temperature range of a sleeping bag, but they’re just one way of accomplishing this goal.

See also:

Check Out All of SectionHiker's Winter Gear Guides!

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  1. Thanks for the excellent information, Phil. BTW, I just picked up an Outdoor Vitals Summit Series StormLOFT 0 degree bag that I’ll be checking out soon. You might want to review of one of their bags at some point – their prices ($239 for the 0 degree) and features are impressive and quality seems very good.

    • We have reviewed some of their gear and been pretty underwhelmed. For example, the only thing I can discern from their website about the bag you’ve chosen is that it has waterproof 800 fill down in it, and only 24 oz (1 lb 8 oz). Compare that to any of the bags listed above and you’ll see that there’s a huge difference. There’s no other information provided about whether the bag has draft tubes or a draft collar, which are pretty dam important on a 0 degree bag. Good luck.

  2. This is one of the harder gear decision for me to make, much more important than choosing a three season bag.
    Thanks for the great list with good comparative information. What’s your thoughts on the Big Agnes bag/pad system?

  3. Commodity type, no-name sleeping bags that are fully and truly competitive with models listed above, are now available at under $200.

    “Most people avoid winter camping and backpacking when temperatures dip below zero anyway since it’s just not that fun.”

    That’s true. And yet — a few degrees below zero isn’t unusual in northern New England. So….depends maybe how you define “fun.”

    • There’s a reason why this isn’t titled 10 Cheapest Winter Sleeping Bags. But I think you’ll have to convince me that the ones you have in mind are competitive on a fill and feature basis. We can start with my three must-have features: draft collar, draft tubes, snag-free zipper. Unlike you (probably,) I have used and tested inexpensive 0-degree bags and been pretty unimpressed with what is being offered.

    • I bought the Montbell Down Hugger 800 #0 for my husband about five years ago and he’s been 100% happy with it. Prior to that he only ever had inexpensive bags and it was a huge improvement in warmth for him.

  4. True again!

    For winter, primarily I’ve used a 1971, REI model with 2.5 pounds (37 ounces) of down (“fill-power” metric wasn’t in use; possibly 500 cubic inches per ounce). With lots of clothing, it’s presently OK to around +10 F.

    For several seasons, I also relied on a NF synthetic bag “rated” to minus 20 F.

    Today’s econo-models (which include the “must-have” features listed above) would undoubtedly be a step up from the REI bag, with which I’ve been generally satisfied.

    For summer, I currently use a $360 Western Mountaineering ultra-light bag, which has a horrible, horrible zipper and, I assume, is in almost no way superior to a $20 bargain-down couch comforter.

  5. Thanks for this detailed review. Very interesting new winer bags with different approaches to staying warm.

    My present winter bag is an LL Bean -20 F. down bag. While filled with “only” 750 fill DWR treated down it is THE best designed winter bag I have ever seen.

    All head and neck cords are elasticized and captured. The draft collar and zipper draft tube are generously insulated and the bag came in a Long size for storage of water bottles, battery powered gear and boot liners.

    Plus I got an outstanding bargain on a one day double discount sale of this bag for an amazing $260.

  6. I am doing an backpacking trip that requires a 20′ or warmer sleeping bag that has to be synthetic due to the environment and weather. We aren’t allowed to bring a down bag. I have researched and I haven’t come up with a bag that is light and warm for under 3 lbs. I did find an Marmot Eco lite 20′ bag that weighs 2 10 oz. Though I’d prefer something warmer since I am a cold sleeper. Anyone know any other options besides that bag. It in a perfect world I would do down its not an option. Any suggestions would be helpful.

    • Rachel, the lightweight cure for making a sleeping bag warmer is to wear warm clothing when you sleep.
      Long johns, a vest of fleece or synthetic fill, etc. PLUS a thin synthetic fleece balaclava which is very important for cool/cold weather camp.

      Also take heavy wool or wool blend “sleep socks” that are worn only at night. Putting your water bottles of hydration bladder in a dry sack and in the foot of your sleeping bag keeps it from freezing overnight.

    • Hi Rachael – Last fall I was too cool in a 5F synthetic bag with overnight temp of 40F … but I made 2 changes that enabled me to be toasty warm at 23F. And I’m a cold sleeper too.

      Change 1: loose-fitting fleece PJs instead of form-fitting duofold thermal underwear. Fleece PJ pants, fleece quarter zip on top, and a fleece hat.

      Change 2: double up my ground pad: from R=3.5 (Ridgerest Solar) to R=6.1 (by adding a Ridgerest Classic).

      Not changed: tent, sleeping bag. No significant wind either night.

      Caveat: the synthetic bag (Snugpak Chrysalis 4) weighs 68.8 oz and packs to 11.5L.

      Some serious studies bear this out, too. Fleece is warmest. And don’t underestimate the importance of good insulation underneath you. You can be losing a fair bit of heat through there and yet feel it’s your bag or PJs that are under-performing. IMO there are situations where you just can’t make up for an inadequate ground pad by going overkill on bag and PJs.

      Good luck!

  7. Philip, I see all the bags reviewed here are 0 F. bags. Could you do a “Deep Winter” sleeping bag review of bags for colder (-20 F. to -40 F.) sleeping bags?

    • Honestly, I’d just list bags from Feathered Friends and Western Mountaineering. If you’re going to go that cold, spend the money for something you can rely on and that will last 20 years. They also hold their resale value pretty well.

    • From borrowing several different bags in this range, I went with the Feathered Friends Snow Goose long. Both the WM and the FF are fantastic but IMO the Feathered Friends version seemed warmer to me. That said this is probably the last season I am going to use it as the thing takes up a lot of room, even with a compression sack and camping in those temps isn’t much fun.

  8. Steve House (famous alpinist) says on Youtube: “When you wake up at 5 a.m. and stuff a humid down sleeping bag into a stuff sack, they’re done. You can only do that once). Thus, unless assured of opportunity to dry the thing out. he “generally” uses synthetic bags for trips of more than one night.

    Unstuffing at home, after single winter night in a well-protected tent, one sometimes finds down nearly drenched and almost useless. The extent of this apparently depends on atmospheric conditions.

    Vapor-barrier liners help avoid the problem, but also entail some disadvantages and complexities.

    For single-night trips, the issue is mostly moot, although the synth bag can offer peace-of-mind, given a sufficiently and horribly large backpack to securely enclose the thing and whatever else.

  9. Philip, i would suggest you consider RAB bags. They have a wide variety of 0 degree bags at competitive prices in the US.
    My 600g fill bag is still going strong after 30 years.
    RAB also do excellent down jackets.

  10. The true answer is; None of the above.. I’ll keep my 1999 Goose Down Western Mountaineering Ultra Lite thank you… It has weathered dozens of near zero nights and days without fail…. Though only rated to 20 degrees, Wearing a Knit Hat, and a full set of Merino Wool Long Underwear and Wool Socks I’ve never been cold in this bag….. Truly worth money over cheaper bags…..with higher prices…

  11. Phillip – i’d Love to see more discussion of synthetic bags. I’m allergic to down and the issues raised here about down and vapor are concerning.

  12. Mr. Werner,
    I do enjoy your insight and advice. I was just thinking the other day how writers always discuss shifting down around in a sleeping bag when discussing baffles. I think a survey of your readers of whether, under what conditions, and how they do this would be very interesting. My thesis is that the only time people shift down is when the down has shifted from its normal place. Although, I never sleep in true winter conditions so it might simply be my lack of experience. Anyway, I think it would be an interesting survey.

  13. Any input, thoughts, or experience with The North Face “The One” bag? Wasn’t even aware of it until recently.

    It’s a roomy, three-layered, modular set-up where you can combine different zipped-in layers to accommodate different temperatures. Reviews are mixed, but generally positive with the main downsides being weight and bulk.

      • Yes, that’s where i noticed it, combing the REI used site. I’ve found some really good deals there. and the condition ratings seem conservative.

        For somewhat extended trips in volatile weather conditions, this modular system would seem to be a good idea. For me, i’m not sure how often those conditions would come together. Usually, i can manage typical temperature ranges by adjusting how much clothing i wear, zipping up my puffy jacket over the foot box of the sleeping bags, etc.

        Love the concept, though, and am a little surprised more manufacturers haven’t explored the idea.

  14. FYI, Fill Power on the Lithium is 800+, not 850 :(

    At first I thought I found quite a steal!

  15. I have 3lb WM bag circa 1993 (or was it 94?) that I’ve long since forgotten the temperature rating. Can I assume that down technology hasn’t improved all that much and it’s all about loft, and that bag is basically a 0 degree bag? Of course, I can always test it in the field, and I’ve taken it down to 10 degrees recently and felt it had plenty of reserve left. I’m taking it to Mt. Washington in Jan, and it should be OK for one night with additional insulation (down jacket and pants) and maybe a liner?

    • It’s not all about loft and your experience with that bag will depend considerably on how you stored it. But if you’ve taken down to 10 degrees, then you know its good for 10 degrees. Why don’t you just call up western mountaineering and ask them what the rating is (for grins, at least).

      • I’ve tried contacting them, and their records back that far have been lost to history apparently.

        I’ve stored the bag well. Trust me, it was work to lug it for 25 years through four states, too many addresses to count, two kids and a divorce. But I always knew I would be putting it use again “someday”. And that day is now, and I’m super happy it’s still in decent shape. Also helped I basically blew my first paycheck on that bag; accounting for inflation, WM bags are actually less expensive today.

        The weather isn’t really cooperating yet for “safely” (i.e. down low, easy bail) testing a bag, but I’m really hoping to see it at -10 or so before mid Jan.

  16. Very detailed review. Thanks for this!

  17. I am looking at a mountain equipment lynx for my adult daughter. My only concern is it is not designed for a woman and does not have hydrophobic down. I found a Women’s Andes 800 (https://rab.equipment/us/women-s-andes-800). Have you looked at RAB bags?

  18. I’ve had good success with using an older 20 degree Marmot synthetic sleeping bag with my 20 degree EE revelation down quilt strapped on top of it. Combined with the right sleeping pad insulation and sleep clothing I’ve slept warm in temps down as low as 9 degree F so far.

  19. Looking over this selection again I’d choose the ThermaRest bag for its high loft 800 fill DWR treated down.

    My LL Bean -20 F. bag has DownTech treated 750 fill goose down and the best design features in a winter bag I’ve ever seen with many details that show the designer actually HAD been a winter backpacker.

  20. I’m partial to a burrito setup myself. WM mummy 35 inside with a Enlighten syn quilt 35 on top. Toasty n not to worried about moisture or weight. Both get me inside the 2.3lbs. N I can cram them both inside a little stuff sack! One for summer and 2 for winter.

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