Best Cold Weather Sleeping Bags of 2024

by Vern Evans

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If you’re ready to push your backpacking or camping out to the shoulder season months — or beyond — your first purchase is likely a cold weather sleeping bag. Of course, what constitutes “cold weather” is subjective. If you live in the southern climes of the United States, 45-degree overnight temperatures might feel chilly. Fairbanks-based staff writer Tyler Freel, in his testing of the best winter jackets for extreme cold set the benchmark at negative 20. For this story, I’ve focused on sleeping bags that would be appropriate for conditions hovering around freezing and down into the teens, but not the extreme cold you can experience in some parts of North America.

If you take only one thing away from this article let it be this: You need a cold weather sleeping bag and a cold weather sleeping pad. If you only add one of these things to your kit, you might be at risk of hypothermia. 

Best Cold Weather Sleeping Bags

Best Cold Weather Sleeping Pads

How I Chose the Best Cold Weather Sleeping Bags

When I’m testing something like the best backpacking water filters or the best hand warmers, I usually have to get a little creative. A manufacturer might say that it will filter 100,000 gallons or hold heat for eight hours, but there’s no way to really know what it’s capable of until you get out there and try it in the real world. But that isn’t the case with cold weather sleeping bags. For this category, there is only one test you’re going to care about: Is the bag as warm as it says it is? And this is measured using a third-party testing protocol: ISO 23537-1:2022, formerly EN 13537. 

Lab Testing Cold Weather Sleeping Bags: ISO 23537-1:2022

In this test, a heated manikin is dressed in thermal underwear, socks, and a facemask. The manikin is then zipped into a sleeping bag and placed on a board with an R value of 4.8. This all goes inside a temperature controlled room. Sensors inside the sleeping bag measure how warm it is once the room drops to a set temperature. While very few sleeping bag manufacturers have their own testing apparatus for this purpose, almost all of them are verified by third parties like that of Kansas State University. 

There are three results that come out of this test: a “comfort” rating, which is the temperature at which you can reasonably expect to be warm; a “limit” rating, the lowest temperature at which you can safely use a sleeping bag; and an “extreme” rating. This is the temperature at which you will probably survive, but are at risk for hypothermia and frostbite. 

There are, however, a few problems with this test. The first is that it doesn’t take your personal physiology into account. Some people run hot and will need less insulation while others run cold and will need more. The other is that manufacturers are not consistent with how they use and advertise the results of these tests. Some will use the limit rating as the stated temperature rating of a sleeping bag, while others will use the comfort rating. Sometimes they’ll test some of their bags, but not others. And sometimes they bury the ISO testing results on the product page in favor of their own internal temperature rating system. 

But the biggest problem of all is how limited ISO testing is. There are plenty of manufacturers who don’t do it at all. This is why your 20-degree Walmart sleeping bag isn’t keeping you warm, and it’s also why a 20-degree ultralight sleeping bag is not always quite up to the job. After all, the easiest way to save on weight and cost is to cut the insulation. Even among the manufacturers that do perform this testing, it’s often limited to certain models and sizes. 

This is a mess, and it makes finding a sleeping bag with the right amount of insulation unnecessarily difficult, especially if you already have a ballpark idea of how many degrees warmer you’re looking for your cold-weather sleeping bag to be. For this story — which focuses on sleeping bags with a limit temperature rating between -10 degrees Fahrenheit and 10 degrees Fahrenheit — I went through the websites of the top sleeping bag manufacturers and pulled sleeping bags’ comfort and limit ISO/EN ratings, along with price, size, weight, and fill, so that you can compare side-by-side. Where this information was missing on manufacturer’s websites, I queried them directly for answers. The full table is below, including 41 compiled picks from 14 different brands.  

To help you get started on your search for the right cold-weather sleeping bag for your needs, I narrowed the field down to six options that most impressed me on warmth to weight, interior space, and value for both down and synthetic models.  

Best Cold Weather Sleeping Bags: Reviews & Recommendations

Best Down: Therm-a-Rest Questar 0F

Key Features

  • Limit Rating: 0°F
  • Comfort Rating: 14° F
  • Weight for a Regular: 2 pounds, 11 ounces
  • Fits Individuals: Less than 5 feet, 6 inches to 6 feet, 6 inches
  • Shoulder Girth: 58 to 66 inches
  • Hip Girth: 58 to 64 inches

Pros

  • Under 3 pounds
  • Comparatively affordable
  • Reasonably roomy
  • Great warranty

Cons

  • Not the lightest pick on this list
  • Cold sleepers may need a warmer bag or a liner for subfreezing temperatures

Cold weather sleeping bags are a balancing act. It has to be warm, yes, but it also needs to be light enough to carry into the backcountry. Some cold weather sleeping bags achieve this by trimming down the classic mummy shape until it feels like you’re in a strait-jacket. Others use so much premium down that they end up costing the same as a down payment on a car. 

The Therm-a-Rest Questar dials in all these competing factors to produce a sleeping bag that is warm and comfortable without breaking the bank or weighing over 4 pounds. It achieves this by opting for the more affordable (if less flashy) 650 fill power down and focusing the majority of it (65 percent) on the top of the bag. Only 35 percent of the bag’s down is in the bottom portion of the bag because the insulation underneath is a less efficient insulator than that on top of your body. Down insulates by lofting, trapping air inside of its tiny wispy filaments. The portion of the down your body is on top of can’t loft, and so isn’t very effective. That’s why you also need a great cold-weather sleeping pad, no matter how the down in your sleeping bag is distributed. 

The only people who shouldn’t grab this bag are those that tend to toss and turn in the night, rolling the bottom of their sleeping bag on top of them. If you do that in this bag, you may wake up shivering in the middle of the night. 

The upshot is that the Questar is a roomier and lighter weight bag for its price point and warmth than the competition. And it’s backed by Therm-a-Rest’s limited lifetime warranty, which is one of the best in the business. 

Best Synthetic: Mountain Hardwear Shasta 0F

Key Features 

  • Limit Rating: 0° F
  • Comfort Rating: 13° F
  • Weight for a Regular: 4 pounds, 9 ounces
  • Fits Individuals: Less than 6 feet to 6 feet, 6 inches
  • Shoulder Girth: 62 to 64 inches
  • Hip Girth: 55 to 58 inches

Pros

  • Affordably priced
  • Great warranty
  • 80 percent of the sleeping bag’s insulation is from recycled material

Cons

  • Tight mummy shape may be less comfortable for side sleepers or broader individuals
  • Heavy

Plenty of backcountry enthusiasts are willing to pay more for a cold-weather ready lightweight down sleeping bag. But if you value affordability over weight, then you’d be better off looking at a synthetic sleeping bag. The Mountain Hardwear Shasta 0F was less than half the price as my best down pick, and is just as warm.

While the Shasta doesn’t resort to redistributing insulation to maximize weight to warmth like the Therm-a-Rest Questar, it does sport the classic mummy shape of so many cold-weather sleeping bags. If you’re new to this term, it’s called a “mummy” shape because these sleeping bags are so restrictive that they force you to sleep flat on your back, without moving (arms folded over your chest is usually optional). 

For plenty of back sleepers, this is comfortable enough, especially since this shape is exceptionally good at conserving heat. For side sleepers, however, it can be a deal breaker. It’s also tough for individuals with broader shoulders or hips as these can be such a tight fit that they are difficult to zip up. But if you’re within the size range of this bag and don’t mind sleeping on your back all night, this is a great choice that will help you save money for the rest of your kit. 

Roomiest: Western Mountaineering Sequoia MF 5F

Key Features

  • Limit Rating: 5° F
  • Comfort Rating: 18° F
  • Weight for a Regular: 3 pounds, 4 ounces 
  • Fits Individuals: Less than 6 feet to 6 feet, 6 inches
  • Shoulder Girth: 66 inches
  • Hip Girth: 61 inches

Pros

  • One of the roomiest cold-weather sleeping bags with an ISO rating
  • Surprisingly lightweight given its size and features
  • Great warranty

Cons

  • Very expensive 
  • Smallest size is still fairly large

If money is no object and comfort is paramount, then you’ll be well served by the Western Mountaineering Sequoia MF. In addition to having one of the roomiest circumference measurements at the hips of anything I looked at, it also has a semi-rectangular shape (as opposed to mummy) that allows for at least some tossing and turning. 

It takes a lot of insulation to warm up all that extra space, but Western Mountaineering keeps the weight within manageable levels by using 850 fill power down. It also has zippers on each side of the sleeping bag, and an adjustable draft collar. If you’re planning to sleep under a tarp instead of a tent, they also make a version made with Gore Infinium fabric, which is fully windproof and very water resistant (see the testing done on the Montbell Versalite, which also uses this fabric, in the best rain jackets for backpacking). 

Best Lightweight: Western Mountaineering Versalite

Key Features

  • Limit Rating: 9° F
  • Comfort Rating: 21° F
  • Weight for a Regular: 2 pounds 
  • Fits Individuals: Less than 5 feet, 6 inches to 6 feet, 6 inches
  • Shoulder Girth: 62 to 63 inches
  • Hip Girth: 53 to 54 inches

Pros

  • Only 2 pounds for a regular size
  • Available in three size ranges
  • Great warranty

Cons

  • Very expensive
  • Not as warm as other picks on this list

This one was a tough call. The Western Mountaineering Versalite clocks in at a cool 2 pounds for a size that would fit a 6-foot individual, but only goes to a limit temperature of 9 degrees. The Therm-a-Rest Parsec, on the other hand, weighs 6 ounces more and goes down to a 0 degree limit rating. But, realistically you can probably find a sleeping bag liner under 6 ounces that will make up that 10-degree difference if you need it, so the Versalite it is.

Like the Western Mountaineering Sequoia, this one gets its light weight from its use of premium down — 850 fill power down. Fill power refers to the number of cubic inches 30 grams of down can fill. So 30 grams of 650 fill power down can fill 650 cubic inches, while 30 grams of 850 fill power down will fill 850 cubic inches. The more cubic inches of lofted fill you have, the better insulated you will be.

There are other factors that will improve or hinder insulation, though, so don’t just look for a sleeping bag with the most loft potential and assume that is a substitute for the ISO testing. For example, some sleeping bags may have down that is poorly distributed, resulting in cold spots. Others may have a loose closure at the neck that allows cold air to seep in during the night when you toss and turn. 

Best Budget Down: Mountain Hardwear Bishop Pass 0F

Key Features

  • Limit Rating: 0° F
  • Comfort Rating: 13° F
  • Weight for a Regular: 3 pounds, 2 ounces
  • Fits Individuals: Less than 6 feet to 6 feet, 6 inches
  • Shoulder Girth: 62 to 64 inches
  • Hip Girth: 53 to 56 inches

Pros

  • One of the least expensive down sleeping bags on the market
  • Not excessively heavy
  • Available in a Gore-Tex version
  • Great warranty

Cons

  • Intense mummy shape may be uncomfortable for some individuals

Down is expensive. Premium down is very expensive. And cold-weather sleeping bags that use down need a lot more down to keep you warm than something like the best down jackets. So down sleeping bags will almost always be more expensive, usually way more expensive than their synthetic counterparts.

While there were a few down sleeping bags in my temperature parameters that were less expensive (the Marmot Ouray, the Marmot Teton, and the Big Agnes Greystone), they were all women-specific sleeping bags. Women-specific sleeping bags are shorter, because women are typically shorter. Shorter sleeping bags means less down. Less down means less expense. 

The Mountain Hardwear Bishop Pass 0F stood out as one of the few regular-length down sleeping bags I looked at that approached the price point of synthetic bags while sticking close to the weight of other down bags. The downside here is that this is a very intense mummy shape (check out the hip measurements before making a final purchase) that may be uncomfortable for some individuals. It also features fewer extras, like a draft collar, compared to other options. (Although they do make a Gore-Tex version for extra weather protection.) But for its price and down bonafides, this one is hard to beat. 

Best Budget Synthetic: Mountain Hardwear Bozeman 0F

Key Features 

  • Limit Rating: 0° F
  • Comfort Rating: 13° F
  • Weight for a Regular: 5 pounds, 7 ounces
  • Fits Individuals: Less than 5 feet, 8 inches to 6 feet, 6 inches
  • Shoulder Girth: 58 to 65 inches
  • Hip Girth: 53 to 62 inches

Pros

  • Under $200
  • Great warranty

Cons

With outdoor gear, you can have two of the following: low weight, low price, great performance. If what you want is great performance and a low price, then the Mountain Hardwear Bozeman 0F it is. It throws weight right out the window (this sleeping bag is 5.5 pounds), but it nails the performance at a sub-$200 price point. 

Best Cold Weather Sleeping Pads: Reviews & Recommendations

Best Overall: Nemo Tensor Extreme Conditions

Key Features

  • R Rating: 8.5
  • Weight for a Regular Mummy: 1 pound, 4 ounces 
  • Available Sizes: Regular, regular mummy, regular wide, long wide

Pros

  • Best warmth-to-weight ratio there is
  • Comes with a handy velcro strap
  • Larger size is a great fit for bigger individuals

Cons

When you’re sleeping out of doors in cold weather, you need protection from two things: the cold of the air and the cold of the ground. Sleeping bags, both down and synthetic, are aces at protecting you from the cold of the air. The cold of the ground, thought? Not so much. That’s what your sleeping pad is going to do. The best cold weather sleeping pads are tested to determine their R value, which is a measurement of their ability to block (resist) cold temperatures from creeping through. The higher the R value, the more protection you’ll have. If the ground is going to be covered in snow or frozen, you want at least an R value of 7. The higher the better. 

Read Next: What Is R Value? It’s Why Your Sleeping Bag Doesn’t Keep You Warm

I tested out the Nemo Tensor Extreme Conditions and if warmth and packability is your goal (it is), there is nothing better. It packs down to less than a Nalgene, it only weighs about a pound, and it’s easy to inflate using the provided pump sack. Three inches of height means you’ll be plenty comfortable but, more importantly, an R value of 8.5 is going to help you sleep a whole lot warmer than you would otherwise. 

Best Lightweight: Therm-a-Rest NeoAir Xtherm

Key Features

  • R Rating: 7.3
  • Weight for a Mummy Regular: 15.5 ounces
  • Available Sizes: Regular mummy, regular wide mummy, and large mummy

Pros

  • Under a pound
  • Mummy shape available across all sizes

Cons

  • Valve and stuff sack aren’t my favorites
  • Not as insulative as the other two on this list

Everything about cold weather camping and backpacking is big and heavy. If you’re trying to achieve a sub-25 pound base weight (the best we can hope for sometimes), then you should seriously consider the Therm-a-Rest NeoAir Xtherm. It’s not quite as insulative as Nemo’s Tensor Extreme Conditions, but it is a touch lighter. Even better, it maintains the weight savings of the mummy shape across the lineup, so you can enjoy the weight savings of shaving off the corners of your pad in the large and wide versions as well. 

Read Next: Therm-a-Rest NeoAir vs Nemo Tensor

Best for Camping: Exped Deep Sleep

Key Features

  • R Rating: 9
  • Weight for a Regular: 3 pounds, 10 ounces
  • Available Sizes: Regular, regular wide, long wide, long extra wide, duo

Pros

  • Very high R rating
  • Less expensive than the other options here
  • Exped offers a two-person version of the Deep Sleep

Cons

If you’re camping out of a vehicle, then you’re probably not all that concerned about weight, leaving you to focus on performance and cost. For my money, the winner for that is the Exped Deep Sleep. While arguably not quite as comfortable as the Exped MegaMat, it’s got a higher R rating, more robust fabric, and lower price point. Even better, it’s offered in a wider variety of sizes, including a two-person pad. 

Cold Weather Sleeping Bags Backed up by ISO Testing

Below is a comprehensive list of available sleeping bags with a limit rating between -10 degrees Fahrenheit and 10 degrees Fahrenheit. 

Sleeping Bag Limit Rating Comfort Rating Price Weight Fits Up To Shoulder Girth Hip Girth Fill
Big Agnes Greystone 0° 3° F 16° F R: $370
L: $370
R: 3 lbs, 5 oz
L: 3 lbs, 9 oz
R: 6’
L: 6’ 6”
R: 60”
L: 63”
R: 54”
L: 57”
600 fp down
Big Agnes Women’s Greystone 20° 10° F 23° F R $270
L: $270
R: 2 lbs, 5 oz
L: 2 lbs, 9 oz
R: 5’ 6”
L: 6’
R: 54”
L: 57”
R: 53”
L: 56”
600 fp down
Big Agnes Lost Ranger 3N1 0° -1° F 12° F R: $450
L: $450
R: 3 lbs, 12 oz
L: 4 lbs, 2 oz
R: 6’
L: 6’ 6”
R: 62”
L: 65”
R: 54”
L: 57” 
650 fp down
Big Agnes Lost Ranger UL 3N1 0° 4° F 17° F R: $670
L: $670
R: 2 lbs, 15 oz
L: 3 lbs, 3 oz
R: 6’
L: 6’ 6”
R: 62”
L: 65”
R: 54”
L: 57” 
850 fp down
Big Agnes Women’s Roxy Ann 3N1 15° -1° F 15° F R: $400
L: $400
R: 3 lbs, 5 oz
L: 3 lbs, 11 oz
R: 5’ 6”
L: 6’
R: 56”
L: 59”
R: 51”
L: 54”
650 fp down
Exped Waterbloc Pro 5° 9° F 21° F S: $800
R: $800
L: $800
S: 2 lbs, 11 oz
R: 2 lbs, 13 oz
L: 2 lbs, 15 oz
S: 5’ 8”
R: 6’
L: 6’ 6”
S: 62”
R: 62”
L: 63”
S: N/A
R: N/A
L: N/A
850 fp down
Exped Ultra -5° -4° F 17° F MW: $900
LW: $900
MW: 3 lbs, 2 oz
LW: 3 lbs, 5 oz 
MW: 6’
LW: 6’ 6”
MW: 64”
LW: 65”
MW: N/A
LW: N/A
850 fp down
Therm-a-Rest Parsec 0° 0° F 14° F S: $530
R: $570
L: $620
S: 2 lbs, 2 oz
R: 2 lbs, 6 oz
L: 2 lbs, 9 oz
S: 5’ 6”
R: 6’
L: 6’ 6”
S: 58”
R: 63”
L: 66”
S: 57”
R: 58”
L: 59”
800 fp down
Kuiu Super Down Sleeping Bag 0° 1° F N/A R: $750
L: $800
R: 2 lbs, 9 oz
L: 2 lbs, 12 oz
R: 6’
L: 6’ 6”
R: 62”
L: 64”
R: 57”
L: 59”
850 fp down
Marmot Women’s Ouray 0° 0° F 14° F $340 3 lbs, 13 oz 5’ 6” 58”  57”  650 fp down
Marmot Women’s Teton 15° 0° F 14° F $310 3 lbs, 10 oz 5’ 6” 58”  57” 650 fp down
Montbell Seamless Down Hugger 800 Expedition  -4° F 10° F R: $720
L: $770
R: 3 lbs
L: 3 lbs, 6 oz
R: 6’
L: 6’ 6”
R: 51” (72”)
L: 55” (77”)*
N/A 800 fp down
Montbell Seamless Down Hugger 800 #0 9° F 21° F R: $560
L: $610
R: 2 lbs, 3 oz
L: 2 lbs, 6 oz
R: 6’
L: 6’ 6”
R: 51” (72”)
L: 55” (77”)*
N/A 800 fp down
Montbell Down Hugger 650 #0 5° F 18° F R: $420
L: $450
R: 3 lbs
L: 3 lbs, 7 oz
R: 6’
L: 6’ 6”
R: 54” (68”)
L: 58” (73”)*
N/A 650 fp down
Montbell Seamless Burrow Bag Expedition 0° F 12° F R: $250
L: $270
R: 5 lbs, 15 oz
L: 7 lbs
R: 6’
L: 6’ 6”
R: 58” (73”)
L: 62” (70”)*
N/A Exceloft 
Montbell Seamless Burrow Bag #0 5° F 18° F R: $230
L: $240
R: 4 lbs, 9 oz
L: 4 lbs, 15 oz
R: 6’
L: 6’ 6”
R: 57” (72”)
L: 61” (77”)*
N/A Exceloft 
Montbell Down Hugger 800 Women’s #0 9° F 21° F $540 2 lbs, 1 oz 5’ 8” N/A N/A 800 fp down
Mountain Hardwear Bishop Pass 0° 0° F 13° F R: $325
L: $345
R: 3 lb, 2 oz
L: 3 lbs, 5 oz
R: 6’
L: 6’ 6”
R: 62”
L: 64”
R: 53”
L: 56”
650 fp down
Mountain Hardwear Bozeman 0° 0° F 13° F S: $170
R: $180
L: $190
S: 4 lbs, 13 oz
R: 5 lbs, 7 oz
L: 6 lbs, 2 oz
S: 5’ 8”
R: 6’
L: 6’ 6”
S: 58”
R: 62”
L: 65”
S: 53”
R: 58”
L: 62”
ThermalQ
Mountain Hardwear Phantom 0° 0° F 13° F S: $670
R: $680
L: $710
S: 2 lbs, 8 oz
R: 2 lbs, 11 oz
L: 2 lbs, 13 oz
S: 5’ 8”
R: 6’
L: 6’ 6”
S: 56”
R: 58”
L: 60”
S: 49”
R: 52”
L: 55”
850 fp down
Mountain Hardwear Phantom Gore-Tex 0° 0° F 13° F R: $830
L: $860
R: 3 lbs, 4 oz
L: 3 lbs, 7 oz
R: 6’
L: 6’ 6”
R: 64”
L: 64”
R: 58”
L: 58”
850 fp down
Mountain Hardwear Shasta 0° 0° F 13° F R: $200
L: $210
R: 4 lbs, 9 oz
L: 4 lbs, 15 oz
R: 6’
L: 6’ 6”
R: 62” L: 64” R: 55”
L: 58”
Thermal.Q 
NEMO Sonic 0° 0° F 14° F S: $550
R: $600
L: $650
S: 3 lbs, 4 oz
R: 3 lbs, 6 oz
L: 3 lbs, 12 oz
S: 5’ 6”
R: 6’
L: 6’ 6”
S: 61”
R: 63”
L: 65”
S: 56”
R: 58”
L: 60”
800 fp down
NEMO Forte Endless Promise Women’s 20° 8° F 21° F R: $220
L: $240
R: 3 lbs, 13 oz
L: 4 lbs, 4 oz
R: 5’ 6”
L: 6’
R: 59”
L: 59” 
R: 54”
L: 54”
Synthetic Zerofiber™ PCR
Rab Mythic 600 Down 10° F 23° F $750 2 lb, 1 oz 6’ 63” 53” 900 fp down
Rab Neutrino Pro 700 Down -4° F 14° F $580 2 lb, 11 oz 6’ 63” 53” 800 fp down
Sea to Summit Trek 0° 0° F 12° F R: $430
L: $460
R: 4 lbs, 3 oz
L: 4 lbs, 10 oz
R: 6’
L: 6’ 4”
R: 62”
L: 66”
R: 59”
L: 63”
650 fp down
Sea to Summit Trek Women’s 15° 3° F 16° F R: $400
L: $430
R: 3 lbs, 9 oz
L: 4 lbs
R: 5’ 7”
L: 6’ 1”
R:57”
L: 61”
R: 57”
L: 61”
650 fp down
Sea to Summit Spark 0° 0° F 14° F R: $650
L: $680
R: 2 lbs, 7 oz
L: 2 lbs, 11 oz
R: 6’ 1”
L: 6’ 6”
R: 61”
L: 65”
R: 53”
L: 57”
850 fp down
Sea to Summit Spark Women’s 15° 5° F 16° F R: $550
L: $580
R: 2 lbs, 1 oz
L: 2 lbs, 4 oz
R: 5’ 7”
L: 6’ 1”
R: 56”
L: 64”
R: 52”
L: 56”
850 fp down
Stone Glacier Chilkoot 0° 0° F 14° F $650 2 lbs, 10 oz 6’ 5” 64” 48” 850 fp down
The North Face One Bag 5° F 20° F $350 R: 3 lbs, 13 oz
L: 4 lbs, 2 oz
R: 6’
L: 6’ 6”
R: 61”
L: 63”
R: 57”
L: 59”
800 fp down and Heatseeker Eco Advanced
Therm-a-Rest Questar 0° 0° F 14° F S: $410
R: $440
L: $470
S: 2 lbs, 9 oz
R: 2 lbs, 11 oz
L: 3 lbs, 1 oz
S: 5’ 6”
R: 6’
L: 6’ 6”
S: 58”
R: 63”
L: 66”
S: 58”
R: 61”
L: 64”
650 fp down
Therm-a-Rest Saros 0° 0° F 14° F S: $220
R: $250
L: $270
S: 4lbs, 5 oz
R: 4 lbs, 15 oz
L: 5 lbs, 4 oz
S: 5’ 6”
R: 6’
L: 6’ 6”
S: 58”
R: 63”
L: 66”
S: 58”
R: 63”
L: 64”
eraLoft Polyester Hollow Fiber 
Western Mountaineering Antelope GWS -2° F 10° F S: $875
R: $905
L: $930
S: 2 lbs, 10 oz
R: 2 lbs, 13 oz
L: 2 lbs, 15 oz
S: 5’ 6”
R: 6’
L: 6’ 6”
S: 62”
R: 62”
L: 63”
S: 53”
R: 53”
L: 54”
850 fp down
Western Mountaineering Antelope MF -1° F 13° F S: $740
R: $760
L: $790
S: 2 lbs, 5 oz
R: 2 lbs, 7 oz
L: 2 lbs, 9 oz
S: 5’ 6”
R: 6’
L: 6’ 6”
S: 62” 
R: 62”
L: 63”
S: 53”
R: 53”
L: 54”
850 fp down
Western Mountaineering Kodiak MF -1° F 13° F S: $835
R: $860
L:  $885
S: 2 lbs, 12 oz
R: 2 lbs, 15 oz
L: 3 lbs, 1 oz
S: 6’
R: 6’ 6”
L: 7’
S: 66”
R: 67”
L: 67”
S: 57”
R: 58”
L: 58”
850 fp down
Western Mountaineering  Kodiak GWS -2° F 10° F S: $985
R: $1,015
L: $1,055
S: 3 lbs, 2 oz
R: 3 lbs, 5 oz
L: 3 lbs, 8 oz
S: 6’
R: 6’ 6”
L: 7’
S: 66”
R: 67”
L: 67”
S: 57”
R: 58”
L: 58”
850 fp down
Western Mountaineering Sequoia GWS 0° F 14° F R: $1,055
L: $1,095
R: 3 lbs, 10 oz
L: 3 lbs, 13 oz
R: 6’
L: 6’ 6”
R: 66”
L: 66”
R: 61”
L: 61”
850 fp down
Western Mountaineering Sequoia MF  5° F 18° F R: $925
L: $960
R: 3 lbs, 4 oz
L: 3 lbs, 7 oz
R: 6’
L: 6’ 6”
R: 66”
L: 66”
R: 61”
L: 61”
850 fp down
Western Mountaineering VersaLite 9° F 21° F S: $705
R: $720
L: $735
S: 1 lb, 14 oz
R: 2 lbs
L: 2 lbs, 2 oz
S: 5’ 6”
R: 6’
L: 6’ 6”
S: 62”
R: 62” 
L: 63”
S: 53”
R: 53”
L: 54”
850 fp down

Cold Weather Sleeping Bags without EN or ISO Ratings

Third-party sleeping bag testing is expensive, to the tune of $1,000 per test. As such, most sleeping bag manufacturers will test some, but not all of their sleeping bags. In my experience, if a sleeping bag manufacturer has tested one temperature rating, generally the temperature ratings of the rest of the series will be accurate. This is particularly true for gear manufacturers like Therm-a-Rest that have their own testing facilities in house that they use. 

However, there are a few sleeping bag manufacturers that eschew the ISO ratings for another reason: They think their own testing and experience outweighs the simulated environment used in ISO testing. This, to me, is quite subjective, but there are a couple of sleeping bag companies who do not test using ISO or EN to have on your radar. While you can likely trust these companies’ bags to perform as advertised, don’t try to compare them to ISO rated bags from other manufacturers.

  • Feathered Friends: Feathered Friends has 40 years of experience making down everything (sleeping bags, jackets, expedition suits), with a focus on mountaineering. While I wish they did use the ISO testing to provide more accurate apples to apples comparison of their products with the likes of Therm-a-Rest and Western Mountaineering (who also have a history of producing products for these communities), at this time this is not information they provide.
  • Wiggys: As staff writer Tyler Freel noted in his review of the Antarctic in our roundup of the best sleeping bags, Wiggys is the gold standard if you are serious about staying warm in extreme cold. Wiggys make sleeping bags with ratings as low as negative 60 (way beyond what the ISO test goes to), and they are what people in Alaska actually use in cold weather. 

What to Look for in a Cold Weather Sleeping Bag

EN or ISO-Rated Temperatures

It was once the case that there was no way to know if a sleeping bag manufacturer’s 0-degree sleeping bag was appropriate for use in sub-freezing conditions — and many weren’t. Fortunately, now there is a standard test for sleeping bags to evaluate warmth: ISO 23537. This used to be called EN 13537, so if you see a sleeping bag referring to their EN rating, that’s OK too.

This test is done in a controlled environment using a heated mannequin with temperature sensors on it, and an insulated sleeping pad — there is even a protocol for what kind of clothing the mannequin is wearing. The test provides three temperature ratings. The first is the comfort rating. This is the lowest temperature at which the average woman will be warm. The next is the limit rating. This is the lowest temperature before the average man starts shivering. Individuals who run especially hot may find that they are still comfortable at this rating, but most will not. Finally, there is the extreme rating. This is the temperature at which you will probably survive, but are at risk for hypothermia and frostbite.  

Further complicating things is that ISO 23537-1:2022 is typically only used for sleeping bags with a hood — in most cases, this is only mummy-shaped sleeping bags. This is pretty frustrating for backpackers and backpack hunters that use quilts or more traditional rectangular sleeping bags, but until a standard is created for these other sleep systems, expect there to be some variation in how warm similarly rated quilts are between manufacturers. You can identify which temperature ratings were done using this standard by looking for ISO-rated comfort and limit temperatures on the sleeping bag manufacturers’ website.

So if you are buying a 0-degree sleeping bag, which of the above ratings does it refer to? Unfortunately, this is not standardized. Some sleeping bag manufacturers state the comfort rating; some state the limit rating. To be sure your sleeping is going to be comfortable at 0 degrees you’ll need to check the technical specs, which will specify comfort and limit ratings. You should really do this anyway, since some sleeping bag manufacturers are using Celsius instead of Fahrenheit, and you may be in for a rude awakening if you purchase a sleeping bag rated for -5 C. 

There are some limitations to the ISO testing protocol. It does not test for temperatures below -25 degrees Fahrenheit. It does not certify sleeping bags for children. And it doesn’t allow for hoodless sleeping. Finally, because it’s taking place in a controlled environment, individual experience may vary. 

But for first-time cold-weather sleeping bag purchases, it’s a God send. Until you are comfortable with the reputation and nuances of your preferred sleeping bag manufacturer, the EN/ISO ratings are going to provide the peace of mind you need to actually make a purchase.

Other Factors to Consider When Choosing a Cold Weather Sleeping Bag

Choosing a Temperature Rating

The best way to know what temperature rating you need for your sleeping bag is, unfortunately, experience. And once you know what you need for, say, 30-degree overnight temperatures, it becomes a lot easier to figure out what you should use for 10-degree overnight temperatures. But if this is your first time purchasing a sleeping bag with an ISO-rating, here are my recommendations.

  • Average men: Select a bag based on its limit rating
  • Average women and men who run cold: Select a bag based on its comfort rating
  • Women who run cold: Choose a bag that has a 10-degree warmer comfort rating

Length

Choosing a cold weather sleeping bag that fits your body is important, but it’s also important to choose one that isn’t too long. Overly large sleeping bags can take longer to warm up, which can be pretty uncomfortable in freezing temps.

Shoulder and Hip Girth

Unfortunately, the most heat-efficient sleeping shape is the mummy-style sleeping bag and almost all of the cold weather sleeping bags available are some variation of this shape. The problem with this style of sleeping bag is that it assumes your body is going to have average proportions, and there are plenty of bodies out there that don’t. I’ve provided hip and shoulder measurements in the above specs to get you started, but be sure to get into your sleeping bag before taking it out into the field so you can be sure that you fit comfortably. 

Weight and Packed Size

Backpackers and backpack hunters should consider, but not overly focus on weight and packed size. If you have to get a bigger backpack to accommodate your cold weather sleeping bag, then so be it: Don’t skimp on the temperature rating of your sleeping bag for lack of space. Individuals who are traveling by other means should pay no attention to weight and packed size at all. 

Price

Steel yourself: True cold weather sleeping bags are pricey, especially if you are looking for a down option. Even the budget options are going to run you upwards of $200, and if you want something made from a premium down, expect to pay well over $600. 

Weather Resistance

Many of the sleeping bags I looked at used a treatment on the down to help it resist water, but some took it a step further and used a weather-resistance shell material. If you plan to use one of the best camping tarps, exposing you to the wind and some rain, this is something to consider. 

What to Look for in a Cold Weather Sleeping Pad

Down and synthetic fills work by trapping air, creating a barrier between the warmth inside your sleeping bag and the cold, cold air outside of it. And sleeping bags that protect you from cold weather have to trap a lot of air to keep you warm. You can see this happening as soon as you pull the bag out of its stuff sack; this ability to trap air is how a down sleeping bag can go from something the size of a toaster oven to a fully lofted sack of warmth. But there’s a catch: If the down can’t loft (fill with air), it’s losing a ton (although not all) of its insulation potential. And there is something that is preventing a huge portion of your sleeping bag from lofting: you. The portion of your sleeping bag that is underneath your body is not lofting, and is not protecting you.

Read Next: Best Backpacking Sleeping Pads

If you are sleeping in a hammock, you can use a product called an underquilt to block the cold, but if you are sleeping directly on the ground (as most cold-weather campers are) you need an insulated sleeping pad. Insulated sleeping pads block the temperature of the ground from seeping through to the other side, and their ability to do this is measured using an R rating. Like with ISO sleeping bag ratings, this is done by a third party using a specific testing protocol, so you can trust that one manufacturer’s 4.2 R rating is the same as another manufacturer’s 4.2 R rating.

R-Rating Chart

While the below chart is providing recommendations based on ambient air temperatures, remember that the temperature of the ground is what your sleeping pad is blocking. In early spring, the ground may be quite cold even though the ambient air temperature is not especially cold. The inverse may be true for the fall months. 

Temperatures Average Manufacturer Recommendation My Recommendation for Cold Sleepers
Warm (55 F or warmer) 1.5 2
Cool (40 F to 55 F) 3 4.5
Cold (25 F to 40 F) 4 6
Extreme Cold (less than 25 F) 5+ 7+

In my experience, the R rating recommendations provided are typically too conservative, especially for individuals that identify as cold sleepers. If you have been struggling to stay warm in an appropriately rated sleeping bag, consider purchasing additional ground insulation before purchasing a new sleeping bag. One affordable way to experiment with this is to purchase the Therm-a-Rest Ridgerest, a closed-cell foam pad that has an R value of 2. On your next outing, try doubling up your current sleeping pad with the Therm-a-Rest Ridgerest. R value is cumulative, so if your current sleeping pad has an R value of 4 and you pair it with the Ridgerest, you’ll end up with an R value of 6. 

The ISO sleeping bag test is done using a 4.8 R-rated sleeping pad: This is the minimum R-rating you should have if you are headed out for a night of sleeping in cold weather. If you sleep cold, I would start with a 7 R-rating for anything below freezing temps. In my experience testing and recommending outdoor gear, having an inadequate sleeping pad is usually the reason someone is sleeping cold; not the sleeping bag. I’ve also found that cold sleepers are especially sensitive to having inadequate sleeping pads: If you sleep cold, don’t hesitate to purchase a sleeping pad rated for extreme conditions for your shoulder season trip. It’s going to make a big difference. 

FAQs

Q: How should a winter sleeping bag hood fit?

While many people like to put one of the best backpacking pillows inside the hood of their cold weather sleeping bag, the hood is meant to go around your head. Cinch it tight enough that it stays in place but not so tight that it blocks your mouth if your head turns sideways while you sleep.

Q: What is the best external fabric for a winter sleeping bag?

Many modern sleeping bags have a durable water resistant (DWR) treatment on the outside to prevent water from seeping inside and swamping the insulation. Beyond that, look for a ripstop nylon or polyester shell fabric that is between 10D and 20D if you are backpacking, higher if weight isn’t a consideration. 

Q: Do women need warmer winter sleeping bags than men?

Women typically run colder than men, and so more often need a warmer sleeping bag. You know your body best, so if you know you run warm, feel free to use the limit rating instead of the comfort rating when making your selection.

Q: What’s the better insulation, down or synthetic?

There are pros and cons to down and synthetic. Down provides the same insulation at a lower weight, but is fragile and does poorly when wet. Synthetic insulation is warm even when wet and less expensive, but is significantly bulkier and heavier. Consider your priorities when choosing a cold weather sleeping bag. 

Read Next: Down versus Synthetic Sleeping Bags

Final Thoughts

Whether you’ve been sleeping cold in the alpine or looking to expand your adventuring out to the shoulder season and beyond, there is a cold-weather sleeping bag for you. I’ve compiled a list of the ISO-rated sleeping bags from top manufacturers, so that you can get started on your search with confidence.

Best Cold Weather Sleeping Bags

Best Cold Weather Sleeping Pads

Read the full article here

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