9 Best 0-Degree Sleeping Bags for Winter’s Cold Weather

Yellow 0-degree down sleeping bag on top of a pad on the snow
Our Favorite 0-Degree Sleeping Bags for Cold-Weather Winter Conditions

Going camping this winter? If so, seriously consider packing a sleeping bag rated down to 0° Fahrenheit. Why? Two good reasons: 1) Plummeting temperatures often catch people off guard, with 500 Americans dying every year of hypothermia; and 2) Many thousands more survive freezing temperatures but shiver miserably through the night!

Here are our picks for the best 0° sleeping bags, for those who like to sleep toasty-warm all night. That’s the club you want to join, right?

This list will examine the best picks from such industry leaders as Mountain Hardware, NEMO, Marmot, Feathered Friends, and Western Mountaineering. From ultralight backpacking sleeping bags to two-person bags for car camping couples, we’ve tried to cover all the options.

But first, a quick rundown on the main factors to consider when choosing your next bag:

Warmth is a function of the thermal layers used — either goose down or synthetic (polyester) insulation.

The warmth of down is rated in terms of its fill power — how puffy an ounce of down is when fully expanded (the ‘loft’). The higher the fill rating, the thicker the insulating layer, and the more warmth provided by that single ounce of down.

Synthetic insulation doesn’t compress or expand the way down insulation does, but it has its own strengths: 1) it’s usually cheaper than down for the same warmth; and 2) synthetics stay warm even when wet, whereas down flattens out when wet and loses much of its warmth.

In terms of packability, a down-filled sleeping bag can compress much smaller than a synthetic-filled bag. That’s a good thing if you’re trying to squeeze all of your gear into a backpack, but if space isn’t a top priority, a bulkier synthetic bag can provide identical warmth.

Shape and size determine the bag’s roominess and comfort. Rectangular bags are roomy and allow the sleeper to stretch and turn. Two-person bags offer extra room for your human or canine partner. A hooded mummy bag is the most constrictive but also the warmest due to it fitting snugly and exposing less of your body to the cold.

Prices range from affordable to break-the-bank, so carefully consider the price/performance tradeoffs of down vs. synthetic bags. Our picks include sleep systems in all price ranges, so choose based on your sleeping needs and whatever best fits your body and wallet.

Table of Contents

Best 0-Degree Sleeping Bags

Best 0-Degree Sleeping Bag for the Money
Mountain Hardware Bishop Pass

Mountain Hardware Bishop Pass

Insulation: 650-fill down
Weight: 3.2 lb

The Mountain Hardwear Bishop Pass is a ‘near zero’ bag designed to keep casual outdoor enthusiasts warm on chilly nights. This 650-fill down bag is rated down to a 13° F comfort level. At this price point, not many other bags come close.

The Bishop Pass is compact, lightweight, and incredibly well-designed, with an efficient mummy shape, a glow-in-the-dark zipper, a draft collar, and a shaped foot box. A two-way zipper allows you to ventilate your feet without unzipping the entire bag.

It’s versatile and light enough for backpacking, offering good warmth when the temperature starts to drop. It’s a truly versatile bag for a car camper or casual backpacker.

Pros: Great value; easy to use; stash pocket; a glow-in-the-dark zipper
Cons: A bit bulky; some may find the mummy shape uncomfortable
Best for: Budget-conscious backpackers



Popular Among Ultralight Backpackers
Feathered Friends Snowbunting EX

Feathered Friends Snowbunting EX ultralight system with 900-fill down

Insulation: 900-fill down
Weight: 2.8 lb

Many people consider the Snowbunting to be the best ultralight zero-degree bag on the market. Yes, it’s pricey, but if compact, lightweight, no-frills packability is your game, look no further.

This bag’s simple design sheds weight by excluding unnecessary pockets or zippers. Its sought-after 900-fill down makes it one of the most thermally efficient bags out there. The Snowbunting will definitely keep you toasty-warm on the coldest of nights.

I’ve heard nothing but excellent feedback when it comes to Feathered Friends products, so I have no reason to doubt this is one of the best ultralight mummy bags you can get your hands on today.

Pros: Ultra-warm; lightweight; highly compressible; made in USA
Cons: Pricey
Best for: Backpack camping and thru-hiking


High-Performance Budget Option
Hyke and Byke Eulos

Hyke and Byke Eulos zero-degree budget mummy sack

Insulation: 800-fill down
Weight: 2.5 lb

If lightweight and budget-friendly are your primary concerns, this is the bag for you. Hyke and Byke is an American company that offers quality products at value prices.

The Eulos gets the job done at a better price point than most down bags on the market. This bag will keep you toasty in the dead of winter, plus it’s lightweight and compresses down to fit the included 10″ x 7″ compression sack.

Rest easy, Hyke and Byke stand by their products. There’s a 30-day money-back guarantee should the bag not perform to your standards. An excellent choice for an outdoor enthusiast looking for a backpacker-friendly option.

Pros: Inexpensive; lightweight; adjustable down distribution; multiple color choices and sizes; a 30-day money back guarantee
Cons: Adjusting the distribution of down can be tedious
Best for: Budget-conscious cold-weather campers



Feature-Rich & Ultra-Comfortable
NEMO Sonic

NEMO Sonic

Insulation: 850-fill down
Weight: 3.3 lb

This tapered mummy bag will keep you warm on the frostiest of winter nights, and the topside Thermo Gills feature lets you vent excess heat on warmer nights. This cleverly-designed and backpacker-friendly bag also has an integrated sleeping pad and pillow.

The Sonic’s unusual spoon shape has extra room for the knees, making it a good choice for side sleepers. If you’re looking for a four-season bag that will get the job done in zero-degree temps, this is an excellent choice.

Pros: Cushy and warm; can regulate bag temp on warmer nights; lifetime warranty
Cons: A snug fit for some larger sleepers
Best for: Outdoor enthusiasts needing a true four-season bag



Good-as-it-Gets High-End Bag
Western Mountaineering Kodiak GWS

Western Mountaineering Kodiak GWS ultralight down for winter and cold weather

Insulation: 850-fill down
Weight: 3.2 lb

This full-featured bag is one of the most thermally efficient sleeping bags on the planet. Plus, the GORE-TEX Windstopper 830 shell is windproof, breathable, and virtually waterproof.

If you’re looking for a premium sleeping bag, this is it. The Kodiak GWS will keep you warm and dry when conditions get harsh. It’s a Made in USA bag with a lifetime warranty that lets you rest easy knowing you have a durable and full-featured bag.

Despite its mummy shape, the Kodiak GWS feels roomy and compresses small for backpacking. Climbing into this bag on a freezing night will be a distinct pleasure. It simply doesn’t get any better than this.

Pros: Large chest circumference is perfect for bigger outdoor enthusiasts
Cons: Expensive
Best for: Outdoor enthusiasts who want optimal warmth and packability



High-Performance Synthetic Option
Marmot Trestles Elite Eco

Marmot Trestles Elite Eco

Insulation: Recycled synthetic
Weight: 3.5 lb

Synthetic fill is the most affordable option for zero-degree bags, but bulkier. Marmot uses 100% recycled material in its Trestles Elite eco, making it both earth- and wallet-friendly. Plus, its roomy cut makes it one of the more spacious mummy bags available.

Unlike down, synthetic fill bags retain their insulation properties when wet. So if your campsites may be cold and wet, carrying a somewhat bulkier synthetic fill bag like the Trestles might be a smart choice.

Stay warm and sleep deeply with the Marmot Trestles Elite Eco, at a fraction of the price of a comparable down bag. For all these reasons, this Marmot bag earns top ratings from customers.

Pros: Inexpensive; doesn’t lose warmth when wet; 100% recycled materials; lifetime warranty
Cons: Too bulky for ultralight backpacking
Best for: Camping where space is not an issue



Zipper-Convertible Quilt into Blanket
Enlightened Equipment Convert

Enlightened Equipment Convert quilt with full length zipper

Insulation: 850- or 950-fill down
Weight: 2 lb

Quilt-style sleep systems are becoming popular with campers looking to save weight in their packs. Quilt systems allow the sleeper to roll over, side-sleep, and get in and out easily. The design is basically a blanket that wraps around the sleeper and is paired with an insulated sleeping pad.

The Enlighted Equipment Convert 0-degree quilt will allow you to be more mobile around your campsite. It’s surprisingly warm, although you may want to wear an insulated cap on colder nights, similar to a mummy bag hood.

The Convert offers a lot of flexibility in staying warm — imagine walking around while wearing it as a quilt or shawl, or sleeping comfortably in an upright position, or even putting your dog under the quilt to share body warmth. Contrast that with the image of hopping around your campfire in a mummy bag!

Pros: Serves as a bag, quilt, or cape; light & packable; made in USA; a 3-year warranty
Cons: Not as thermally efficient as more closed traditional designs
Best for: Side sleepers and campers looking to cut pack weight


Roomy (But Bulky) Rectangular Bag
Teton Sports Celsius XXL

Teton Sports Celsius XXL rectangular 0-degree sleeping bag

Insulation: Synthetic
Weight: 7 lb

Is a bulky carry not a concern? You’ll love this sleeping bag if you have room in your vehicle or ample pack. This bag will keep you toasty, and the flannel lining is super cozy. Plus, it treads gently on your wallet.

At seven pounds, weight is the most notable drawback of this bag. It’s the heaviest single-person bag we recommend. But if hooded rectangular bags like this are in your childhood memories, you’ll revel in this most spacious and luxurious of sleeping bags.

Let’s be clear — this is not ideal as part of a backpacking sleep system. But in roomy or unchallenging scenarios, it’s a guarantee of a good night’s sleep.

Pros: Spacious; inexpensive; warm, a decent warranty
Cons: Large and bulky
Best for: Car campers or those willing to pack a bulky and heavy system



Big & Burly Two-Person Bag
Teton Sports Fahrenheit Mammoth

Teton Sports Fahrenheit Mammoth

Insulation: Synthetic
Weight: 16.5 lb

Ah, decadence! So you want to cuddle with your favorite human or canine companion? Then the Fahrenheit Mammoth is for you — a roomy two-person bag that will keep the heat turned up even when the temperature drops into single digits. But don’t forget to bring a roomy tent along.

The Fahrenheit Mammoth tips the scales at nearly 17 pounds, by far the heaviest sleeping bag we’ve ever reviewed. An integrated mummy-style hood will cinch down to keep you and the plaid flannel liner snuggly warm.

This bag is an absolute whale, so it’s not a realistic option for backpackers. But glampers or car campers with room to spare will find the Fahrenheit Mammoth can transform a chilly tent into an oasis of warmth.

Pros: Good warranty; a truly comfy two-person bag
Cons: Very bulky and heavy
Best for: Car camping couples or glampers


Factors We Considered When Analyzing Products

Backpacking camping setup on top of a snowy surface in the cold weather of winter
There’s a lot to mull over when considering your next cold-weather bag

Picking your next sleeping bag for those cold weather endeavors can be challenging. That’s why we took the following eight factors very seriously when choosing bags to recommend to you.


From the outer fabric to the insulation to the stitching, your zero degree bag must be made from quality materials if it’s to do its job, season-after-season. That’s why we’ve searched for bags made from top-notch materials that won’t rip, tear, or fail you when you need ’em most.

Down vs. Synthetic

Down filling delivers the most warmth for weight. Down fill is rated from 350-900; this number represents the number of cubic inches one ounce of down can fill.

More filling means more air pockets and more insulation. A 450-fill sleeping bag can insulate as well as a 900-fill bag, but it would have to be bulkier and weigh considerably more.

Synthetic filling also has its benefits: it’s considerably cheaper, and in a survival situation, it will retain its insulation properties even when wet.


The snug-fitting mummy bag is the most efficient shape for heat retention, and it tends to compress into a smaller bag.

Like your old Coleman bag from childhood, rectangular bags offer more room for side sleepers and active sleepers, but it will always be bulkier and heavier than a mummy bag.

Quilt-style bags are basically blankets that a sleeper wraps themselves in while lying on an insulated sleeping pad. This accommodates lots of movement when sleeping. These bags are lightweight and very packable.

The main drawback of quilts is that they don’t seal tight like a traditional sleeping bag with zippers, and thus are not inherently efficient. Sleepers will likely want an insulated head covering.


When creating a more minimalist backpacking kit, every ounce and cubic inch counts. If you’re a glamper or car camper and have the space for it, it’s feasible to choose a heavier and bulkier option that’s guaranteed to deliver a luxurious outdoor sleep experience.

On the other hand, if lightweight is important to you, a mummy-shaped bag with an 800+ fill count will offer the most warmth per ounce.

Packed Size

Sleeping bags, especially when down-filled, are highly compressible. Down bags can be jammed into 15L stuff sacks and take up minimal space in your pack. Our favorite synthetic bag, the Marmot Trestles 0, will need a 20L stuff sack.

Fill Power

Ever wonder what it means when a manufacturer assigns a number to your puffy coat or sleeping bag? That number is the fill rating, typically 350-900. This rating represents the number of cubic inches that one ounce of down will occupy.

More volume (higher fill power) means more air pockets. More air pockets mean more insulation per unit of volume. Therefore a 0° F. bag with 350-fill will keep you just as warm as a 0° bag with 700-fill. But the 350-fill will require twice the mass of down to provide the same warmth as the 700-fill bag.


Any modern sleep system includes a synthetic fabric shell. All of the bags reviewed here have 100% synthetic shells, except for the Teton Sports bags. These also have flannel liners for extra comfort but at the expense of packability and low weight.

Nylon shells are vulnerable to sharp edges and heat, but with basic maintenance and care, all of the bags we picked should give you many years of reliable use. Plus, all of the sleeping bags we recommend come with manufacturer warranties.


Zero-degree bags range widely in price. Depending on your sleep system needs, you might not need to break the bank — synthetic sleeping bags and inexpensive down bags may offer everything you need. If budget is not an issue, then ultralight campers can’t beat the Western Mountaineering Kodiak GWS overall or the Feathered Friends Snowbunting EX.

Which 0-Degree Bag Will Keep You Warm?

Hiker lying in a sleeping bag looking out of their tent as the sun rises on the horizon
Grab a bag, stay warm and comfortable, sleep well, thrive in the great outdoors

We hope this review helped narrow your search for the a zero-degree sleeping bag. Technology is always improving, and these bags are some of your most state-of-the-art options.

Remember: when the temperature drops, it’s important to stay warm and get a good night’s sleep so you’ll wake up refreshed to tackle a new day. Sleeping bags rated down to zero degrees will do just that.

Browse our picks and choose the one that best suits your needs — perhaps a budget option that utilizes synthetic fill, or a high-end bag with 850-fill down like the Western Mountaineering Kodiak GWS.

Ultralight backpackers will love quilt systems like the Feathered Friends Snowbunting EX or the Enlightened Equipment Convert. Just be aware of the quilt system tradeoffs between light weight and small pack size vs. the less efficient thermal properties.

If lightweight packability is not a priority for you, a synthetic mummy bag like the Marmot Trestles Elite Eco, or a bulkier rectangular bag like the Teton Sports Celsius XXL and Fahrenheit Mammoth will surely keep you snug when the temperature drops.

If you’re looking for the warmest option, and packability is a top priority, you can’t beat the Western Mountaineering Kodiak GWS. We found this to be the absolute best bag on the market in terms of overall warmth and packability.

No matter which of these bags you choose, may you sleep toasty-warm and be safe from chattering teeth and membership in the 500 Club!

Last Updated on March 19, 2024

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Joe Nemiroff

Joe is a burly outdoorsman who loves chopping wood, prancing along trails, and sipping whiskey by the campfire. He gets into the mountains as often as possible to keep the demons at bay.

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