9 Best Cold Weather Sleeping Bags (Sub-Zero & Extreme Cold)

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When temps are freezing to sub-zero your survival depends on staying warm. These are my favorite cold weather sleeping bags.

best cold weather sleeping bags for sub zero temps

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Ascent 1100 -15F Down Bag



Conundrum Sleeping Quilt



Parsec 0 Sleeping Bag



Bishop Pass Sleeping Bag



Big Bay Sleeping Bag



Crescent Lake Sleeping Bag



Echo Park 20F



Little Red 20 Sleeping Bag


Did you know that it takes just over 10 minutes for a person to get frostbite in 0°F temperatures with only a mild wind?

Now imagine 8 hours of unrelenting cold overnight.

Your sleep system is your last line of defense against injury and (in some cases) even death.

I don’t say that lightly.

In this article, I share my 9 favorite cold weather sleeping bags; ranging from sub-zero, bone-chilling cold to your average chilly winter night.

There are thousands of different sleeping bags on the market, so let’s cut through the crap and get straight to the best of the best.

How to Choose The Best Cold Weather Sleeping Bag For Extreme Cold Conditions

Choosing the best cold weather sleeping bag is about more than just Temperature Rating. As you shop for the sleeping bag that’s best for you, consider these 6 factors:

  1. Temperature Rating
  2. Insulation Material
  3. Sleeping Bag Shape
  4. Zipper Design & Location
  5. Weight
  6. Additional Features

Let’s expand upon each.

Related: The Best Sleeping Bags For Camping

Temperature Rating

Sleeping bags are rated for temperature using a standardized process outlined in either EN 13537 or ISO 23537.

What is this process?

Essentially, a manikin rigged with thermal sensors is used in a controlled environment to rate the insulation power of a sleeping bag. Because a standard process is used every time, sleeping bags rated according to either EN 13537 or ISO 23537 criteria can be compared apples to apples.

Note: ISO 23537 became the standard in 2016. Prior to that, the standard was EN 13537. If you’re researching cold weather sleeping bags and come across EN 13537 ratings, note that it’s a similar and still useful rating.

These processes rate 3 different temperature limits for sleeping bags:

  • Comfort Temperature: Lower limit of the comfort range for a sleeper in a relaxed position
  • Limit Temperature: Lower limit of comfort range for a curled up sleeper
  • Extreme Temperature: Lower limit for survival; the sleeper will feel cold but will survive

When you’re shopping for the best cold weather sleeping bag, you want to make sure the coldest weather you’d likely run into is above the Limit Temperature for the sleeping bag. Ideally it’s above the lower end of the Comfort Temperature range.

If there’s even a remote chance the temperature could drop below the Limit Temperature for a sleeping bag, you don’t want to buy that sleeping bag.

In the event that a sleeping bag doesn’t have a specific temperature rating, it probably has a general classification such as “Summer” or “3-Season.” If that’s the case, REI has a guide that can be used to turn those vague terms into approximate temperature ranges:

  • Summer: Above 35°F
  • 3-Season: 10°F-35°F
  • Winter: Under 10°F

Note that the low end of these ranges is the Limit Temperature as defined above.

Insulation Material

Sleeping bag insulation can be made of two different materials:

  • Synthetics, generally polyester
  • Down feathers, generally duck or goose (duck is better)

While both are capable of keeping you warm, there are some key differences between the two.

Benefits of Synthetic Sleeping Bags

  • Dry more quickly
  • Non-allergenic
  • Better insulation in wetter conditions (usually)
  • Usually less expensive

Benefits of Down Sleeping Bags

  • High-quality down bags can be much lighter for the same temperature rating
  • Compress more easily
  • Better insulation in dry conditions
  • Longer lifespan when treated well

For more information, check out our Synthetic vs Down Sleeping Bag comparison.

Sleeping Bag Shape

Sleeping bags come in 4 different shapes:

  • Rectangular
  • Semi-rectangular (ends taper inwards)
  • Mummy
  • Double-wide (rectangular for two people)

The first three descend from most comfortable/spacious to least comfortable/spacious. However, spaciousness is inversely proportional to insulation power. That means the best cold weather sleeping bag probably will be a mummy sleeping bag. However, if you’re a big guy be aware that mummy bags can be more restricting.

Zipper Design & Location

The zipper is the weak point in a sleeping bag. That’s where the insulation tapers off, giving way to a potential avenue for warm air to escape. As you look for the best cold weather sleeping bags, take a long look at the zipper. You’ll want to focus on three aspects of the zipper:

  • Durability and quality of construction
  • Length
  • Location

Durability and quality are important (obviously) because a well-designed, well-made zipper will allow less warm air to escape and is much less likely to break. A stuck zipper that won’t properly seal your sleeping bag is a recipe for disaster.

Length is important because shorter zippers reduce the risk of warm air escaping. Many mummy style sleeping bags feature half-zip zippers with fully-enclosed feet. However, the downside to these types of sleeping bags is a lack of temperature regulation in warmer temperatures. You can’t just stick your feet out to cool down.

Location isn’t quite as important on a cold weather sleeping bag unless you want to connect two sleeping bags to make one larger sleeping bag. In this case, you’ll want to choose one left-handed zipper bag and one right-handed zipper bag, making sure the zippers are the same length. Note that the major downside here is you likely lose some insulation power. However, having shared body heat can mitigate that.


Weight is more about you being able to carry the sleeping bag on your pack if you’re backpacking. Heavier sleeping bags are not warmer by default. Remember that down vs synthetic discussion above? Synthetic sleeping bags actually weigh more for the same insulation power.

If you’re looking to cut weight, mummy sleeping bags should be given strong consideration. They’re narrower and use less material with the trade-off being their restrictiveness. Semi-rectangular sleeping bags will have more weight but also be more comfortable.

7 Additional Features On Cold Weather Sleeping Bags

As you’re shopping for the best cold weather sleeping bag, consider these additional features:

Hood With Drawstring // Extreme cold weather sleeping bags often have a constricting head design with a drawstring, giving you the ability to really seal yourself in.

Baffles // Baffles are designed pockets of insulation and are intended to keep the insulation in specific areas. You can see these as the geometric stitching/seams visible from the outside of the sleeping bag. They’re especially important in down sleeping bags, as down feathers tend to shift more than synthetic polyester.

Face Mufflers // Face mufflers are baffles around the face that localize insulation to keep you warmer.

Pockets // Whether it’s tents, backpacks, or sleeping bags, pockets are a huge part of your camping and survival gear. Consider the pocket location in your sleeping bag (if applicable). This is more important in restrictive mummy sleeping bags, as pockets near your hands to store your phone or flashlight can be especially helpful.

Footbox Shape // Also more important in mummy sleeping bags, does the footbox round off the end or have a boxier, trapezoidal shape? A trapezoidal footbox provides a more natural shape for your feet, providing more comfort and potentially placing less stress on the sleeping bag material because your feet aren’t abnormally crammed inside. The downside, however, is more material/weight.

Sleeping Pad Compatibility // Some sleeping bags are “bottomless” in design, by which I mean they don’t have insulation on the bottom. Instead, they have either a sleeve or hooks where a sleeping pad slides in or attaches. The major upside to these sleeping bags is they’re lighter and store away more compactly. If you’re bringing a sleeping pad anyway, you may want to consider one of these sleeping bag designs.

My Top Picks

SubZero – Men’s

The Western Mountaineering Bison GORE-TEX INFINIUM Sleeping Bag: -40F Down

Western Mountaineering Bison INFINIUM Sleeping Bag

Best For: Sub-Zero mountaineering and camping in the most extreme cold conditions.

  • Shape: Mummy
  • Fill Type: Goose down
  • Fill Power: 850+
  • Temp Rating: -40°F
  • Outer Shell: GORE-TEX INFINIUM
  • Inner Lining: GORE-TEX INFINIUM
  • Weight: 2 lb 10 oz (regular) | 2 lb 13 oz (long)
  • Fits Up To: 72″ (regular) | 78″ (long)

Western Mountaineering is known for making sleeping bags designed to withstand extreme cold, but the Bison with GORE-TEX INFINIUM takes warmth to a whole new level!

Designed for the most extreme mountaineering and winter camping situations, the Bison offers an unparalleled warmth-to-weight ratio.

Even the oversized large version that fits sleepers up to 6’6″ weighs less than 4 lbs, which is less than many of the other sleeping bags on this list!

Combine that with the trusted weather and moisture-combating power of GORE-TEX and this sleeping bag is easily our choice for the best cold weather sub-zero sleeping bag.

SubZero – Womens

Rab Ascent 1100 Women’s -15F Down Sleeping Bag

Best For: Sub-Zero mountaineering and camping at high altitudes

  • Shape: Wide mummy
  • Fill Type: Doose down
  • Fill Power: 650
  • Temp Rating: -15°F
  • Outer Shell: 30D Recycled Pertex
  • Inner Lining: 20D Recycled Nylon
  • Weight: 3 lb 12 oz
  • Fits Up To: 72″ (regular) | 78″ (long)

The wide mummy shape of this sub-zero sleeping bag for women allows you to spread out without giving up warmth, which means better rest and more energy for tomorrow’s adventures.

The proprietary Pertex Quantum fill does a fantastic job of blocking wind, which can be a literal lifesaver when you are camping at altitude, and it’s our pick for the best cold weather sub-zero sleeping bag for women.

Cold Weather Backpacking – Unisex

Conundrum -10F Sleeping Quilt

Best ForWinter backpacking trips in temperatures well below freezing.

  • Shape: Quilt
  • Fill Type: Grey duck down
  • Fill Power: 850/950
  • Temp Rating: -10°F
  • Outer Shell: Nylon
  • Inner Lining: Nylon
  • Weight: 1 lb 9 oz to 3lb 1 oz
  • Fits Up To: 66″ to 84″

Enlightened Equipment specializes in ultralight gear for backpackers and thru-hikers, and they are leading the movement to use quilts instead of traditional sleeping bags.

This is their warmest product and comes in a wide range of sizes, which means you can be sure to find one perfect for your body type.

You can also choose from either 850 or 950 down fill. In fact, you can even customize the entire quilt to your exact personal needs!

Zero Degree – Men’s

Therm-A-Rest Parsec 0 Degree Sleeping Bag

Best ForFour season camping and backpacking in extreme cold zero degree conditions.

  • Shape: Mummy
  • Fill Type: Nikwax Hydrophobic Down
  • Fill Power: 800
  • Temp Rating: 0°F
  • Outer Shell: 20D Nylon
  • Inner Lining: Nylon
  • Weight: 2 lb 2 oz (small) | 2 lb 6 oz (regular) | 2 lb 9 oz (large)
  • Fits Up To: 66″ (small) | 72″ (regular) | 78″ (long)

Therm-A-Rest are specialist in camping sleep systems and the Parsec is one of my all time favorites.

A thoughtful design feature is the wider shoulder area that allows for extra base layers (read: your puffy jacket) beneath the bag.

Zero Degree – Women’s

Mountain Hardware Bishop Pass

Best ForZero degree camping and backpacking for women.

  • Shape: Mummy
  • Fill Type: Flourine-free down
  • Fill Power: 650
  • Temp Rating: 0°F
  • Outer Shell: 20D Nylon
  • Inner Lining: 30D Nylon
  • Weight: 3lb 2.8 oz (regular) | 3lb 7oz (long)
  • Fits Up To: 68″ (regular) | 72″ (long)

Kudos to Mountain Hardware for continuing to make high performance products for women.

This bag provides additional insulation and the unique “Performance Plus Mummy cut” keeps the bag close to the body for increased insulation without sacrificing the room the wiggle around a little bit. That means you can sleep like a human and not an actual mummy.

Car Camping – Unisex

Coleman Big Bay O Degree Sleeping Bag

Best ForCar camping in sub-freezing temperatures and cold weather conditions

  • Shape: Mummy
  • Fill Type: Synthetic
  • Fill Power: N/A
  • Temp Rating: 0°F
  • Outer Shell:
  • Inner Lining:
  • Weight:
  • Fits Up To:

This is a fantastic four season cold weather sleeping bag for car camping and weekend excursions.

Coleman has been making quality products longer than any of us have been alive and the Big Bay 0 Degree Sleeping bag continues with that tradition.

This is a heavy bag, but you’re driving right to your campsite, so what do you care?

Budget Picks – Unisex

ALPS Mountaineering Crescent Lake Sleeping Bag

Best ForA budget-conscious cold weather sleeping bag for tent camping.

  • Shape: Mummy
  • Fill Type: Synthetic
  • Fill Power: N/A
  • Temp Rating: 0°F
  • Outer Shell: Polyester
  • Inner Lining: Polyester
  • Weight: 5 lb 3 oz
  • Fits Up To: 80″

No one is going to mistake this 5lb hulk of a bag for ultra light gear anytime soon, but with an MSRP of only $99.99, this bag is a great value for the money.

At that price you also can’t expect it to be a waterproof bag (it isn’t), but its large, comfy, warm, and great for overnight family camping trips.

Comfort Pick – Unisex

Big Agnes Echo Park 20F Sleeping Bag

Best ForA winter sleeping bag for campers who value comfort.

  • Shape: Mummy
  • Fill Type: Synthetic
  • Fill Power: N/A
  • Temp Rating: 20°F
  • Outer Shell: Ripstop Nylon
  • Inner Lining: Cotton/Poly blend
  • Weight: 4 lb 12 oz
  • Fits Up To: 78″

Is it a coincidence a brand named Big Agnes makes a great sleeping bag for big guys? Perhaps…but I like to think it’s no accident!

This monster is a sleeping bag and comforter all in one (depending on how you’d like to use it).

It can handle campers up to 78″ tall, and also has extra wide girth in the shoulders and hips for guys with a bit more “natural insulation” in their mid-sections.

Cold Weather Sleeping Bag For Kids

Big Agnes Little Red 20F Sleeping Bag

Best ForA cold weather sleeping bag for kids that protects from freezing temperatures.

  • Shape: Mummy
  • Fill Type: Synthetic
  • Fill Power: N/A
  • Temp Rating: 20°F
  • Outer Shell: 20D Polyester
  • Inner Lining: 50D Polyester
  • Weight: 1 lb 11 oz
  • Fits Up To: 48″

Having a sleeping bag that is the proper size for your body is a key to staying warm, thus, and your kid needs a properly sized bag just as much, or more than you do.

The Little Red 20F is a new release from Big Agnes and has the same level of quality, craftsmanship, and design as their full “adult-sized” sleeping bags.

Cold Weather Sleeping Bag FAQ

What Sleeping Bag Shape Is The Best For Cold Weather?

The best sleeping bag shape for cold weather is a mummy shaped bag. Their form fitting design traps in heat and provides more overall warmth than other shapes.

What Type Of Sleeping Bag Is Best For Cold Weather?

The best type of sleeping bag for cold weather and sub-zero temperatures is a down sleeping bag. They provide the most warmth with minimal weight.

Do Sub Zero Sleeping Bags Work?

Yes, sub zero sleeping bags from reputable manufacturer’s are built to withstand temperatures below 0 degrees fahrenheit, and some bags are rated to temps as low as -40.

My Testing & Review Process

First, I spent 20+ nights camping in the cold weather and nasty conditions. Don’t worry, I loved (almost) every second of it! I’m a fanatic about testing and researching gear and I love to go camping in colder temperatures.

I started with the sleeping bags I already owned. Both my wife and I go camping and being the gear snob that I am, I own multiple sleeping bags already. 

Next, I reach out to my many friends who share my passion for the outdoors. If I haven’t used it, there is a darn good chance they have.

Finally, I examined 100’s of verified reviews from other first-hand users.

As always, my goal is to provide you with the most accurate and unbiased review possible.

Features I Considered

I compared each of the sleeping bags by looking at the following list of features:

Shape: The shape of a sleeping bag significantly impacts its ability to keep you warm.

Fill Type: All of the bags on my list are down or premier synthetics designed to mimic and improve upon the characteristics of down.

Fill Power: We’re always looking for the most power at the lowest weight

Low-End Comfort Temp: This is how cold it can get while you still comfortably sleep through the night. Keep in mind this is often a much warmer temp than the survival rating, which is how cold it can get while you shiver away all night but still survive. Don’t get me wrong…survival temp is VERY important. But, always remember that comfort temp is what matters for a good nights sleep.

Outer Shell: The shell protects the bag (and you) from the elements. So it’s design definitely matters.

Inner Shell: The inner shell is what is next to my body and needs to be both moisture-wicking and rugged.

Weight: If you are backpacking, weight is of critical importance. We want maximum warmth with minimal weight.

Fit: One of the best things about humans is that we are all different! As such, what may be a great size for one person may be awful for another. So I try to simply comment on the size and who it is best suited for rather than Iigh it into my scoring criteria.

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Bryan Hunter

Bryan is the founder of The Outdoor Authority and an avid outdoorsman who has backpacked through South America, hiked in the Galapagos, and spent countless nights camping all across the United States.