Insulation
With a 0 degree Fahrenheit temperature rating, this synthetic insulated sleeping bag will keep you warm in almost all conditions. The wave construction improves the loft of the insulation without increasing the weight. The insulation used is SpiralFit LT high loft insulation. One of the great features of synthetic insulation is that it continues to function well when wet and dries quickly.

Breathability
The snag-free zippers run smoothly and feature an insulated drag tube. You can order the bag with the zipper on whichever side is more comfortable for you. It runs almost down to your feet. This, combined with the fold-down zipper is great for providing breathability when you heat up during the night. Additionally, the materials inside are moisture-wicking and dry quickly.

Comfort
This sleeping bag has a relaxed mummy shape with a trapezoid-shaped foot box. You can choose from regular size, long, or wide. There is even a small zippered pocket on the top side of the bag for easy access to small items, such as a cell phone or headlamp.

Portability
The included compression sack definitely helps to contain this fluffy bag, but it is still pretty big. Luckily, it only weighs about 5-pounds, which is a bit much to carry through a mountain pass but is fine for shorter trips.

Insulation
To prevent any heat loss, besides the 800-fill down insulation, there is both a full-draft collar and an implemented draft overlap. All in all, this is enough to hold up in temperatures that stay above 0 degrees Fahrenheit.

Breathability
While there is a half-way center zipper that allows for entry and exit, it could have been longer and side zippers would have been ideal. Unfortunately, the Inferno is severely lacking in this area.

Comfort
Due to the manner in which this zero degree sleeping bag was designed, it is simple to sleep in it with multiple layers of clothing on. The North Face provides you with the option of either a long or regular-sized version. If you are over 72 inches in height, then you can select the long version which comfortably fits lengths of up to 79 inches.

Portability
As with most sellers, The North Face includes both a compression sack and storage sack for easy transport and carry. As a bonus, there is an internal pocket that can be used as a storage location.

Overall
For pure performance, this bag delivers in every area you want. It is highly insulated and is designed to prevent drafts, while also being comfortable to the touch. However, the zipper design is lacking and they may prove to be too big of an issue for you.

Insulation
Kelty, the makers of the Cosmic 0 Degree, secures a 0-degree rating by utilizing 600-fill down that has been treated with a water-resistant finish and a full draft collar for sealing out cold drafts.

Breathability
The 60-inch dual-sliding zipper, which covers most of the sleeping bag, is crafted with an anti-snag design.

Comfort
Proving plenty of room for your feet is the natural-fit foot box and in conjunction with the ripstop polyester that feels terrific against your skin, comfort is certainly not an issue here. Again, you get the option for either a long or regular version of the same bag. The only difference is the long version adapts for a longer length (78 inches), shoulder girth (64 inches) and width girth (60 inches).

Portability
While there is a stuff sack that comes included, the sleeping bag itself is rather bulky. Thus, it can be a hassle to consistently fit it inside of the sack when you are traveling.

Overall
Strip away the bulkiness and yet again, you are left with the best sleeping bag for cold weather that could easily be number one on this list. That speaks to the quality at play here and the fact that one small design issue can make the difference.

Insulation
Being rated to keep you toasty in temperatures that do not drop below 15 degrees Fahrenheit, this will adapt for average winter nights. To accomplish this, Big Agnes designed their King Solomon with 600fill down insulation and a ripstop nylon shell with a DWR finish to repel water.

Breathability
No doubt, these cold-weather sleeping bags for cold weather has many ways of access. With double zippers on both sides, you can enter from either side and produce an ample amount of ventilation. In addition, when it is unzipped it can be used as a comforter.

Comfort
Big Agnes takes pride in their dubbing of “The Mother of Comfort” and King Solomon is a great example of why. This is specifically designed to fit two people or can be utilized as one if you like a lot of excess room while sleeping.

Portability
As compared to the last double sleeping bag, this is significantly lighter and easy to compress. With the included mesh storage sack and nylon stuff sack, portability is a breeze.

Overall
In spite of the somewhat disappointing temperature rating, although it will keep you insulated on average winter nights (depending on where you are), King Solomon certainly justifies its name due to its quality.

Insulation
Beginning with the interior, the Snowmass is filled with down, which insulates you by keeping a layer of heat near you at all times. Along with this, there is added warmth with the mummy-style head area, which you can curl into and rest assured that the heat from your head isn't pouring into the cold outdoor air.

Breathability
The metal anti-snagging YKK zippers unzip on one side until about one foot above the bottom of the bag. This makes it very easy to get in and out of the bag. It also provides great ventilation if you happen to get too hot in the night.

Comfort
After fluffing up the fabric to get it ready, it is a comfortable bag. A few reviewers wish that they would have gone up a length. The Hyke and Byke is available in three sizes, short, regular, and long. They claim to accommodate persons ranging from 5’ to 6’6 feet tall.

Portability
As for your ability to pick up and go with this bag, it is relatively lightweight; it weighs in at around 4-lbs. It packs down nicely into it's carrying case that is provided so that you should still have plenty of room in your backpack for clothes, food, and other outdoor's survival paraphernalia. To top it off, the Snowmass is quite durable, as it is constructed with a strong 100% nylon ripstop fabric that is also water repellent.

Insulation
Western Mountaineering also decided to utilize down insulation with their sleeping bag, in the count of 850-fill. But, the high-thread-count in the fabric shell of the bag seals in that insulation to deliver the maximum amount of warmth possible (to the degree of 10 degrees Fahrenheit). Plus, the interlocking draft tubes prevent drafts from entering in.

Breathability
With its full-length, YKK zipper, in times where the temperature is warmer than usual, you can simply unzip the bag to allow extra breathing room and ventilation.

Comfort
To allow for extra layering, when the climate outdoors is insanely cold, there is a wide shoulder girth. There are three different sizing options that you can select from and they all allude to your height. The options are for 5-foot-6-inches, 6-foot, and 6-foot-6-inches.

Portability
Not only does the 850-fill down insulation deliver impeccable warmth, but it is also highly-compressible making it easy to pack. Speaking of packing, this sleeping bag comes with a storage stuff sack.

Overall
Even with a slightly higher temperature rating of 10 degrees Fahrenheit, this is as elite as it gets. If you think about it this way, in climates that do reach in the negatives, the wide shoulder girth allows you to layer on extra clothing.

Insulation
Not only does the Phantom Torch 3 feature 800-fill down insulation, but the down has also been treated with a repellent that resists moisture and retains loft in damp conditions. Also, the face gasket blocks away drafts and helps to achieve a temperature rating of 3 degrees Fahrenheit.

Breathability
A durable two-way zipper is present on the side of the sleeping bag (which you can choose) for an easy exit and extra ventilation.

Comfort
With 10D nylon fabric that is soft to the touch, a natural foot box, and six-chamber hood design, you are not only promised superb warmth but also comfort. If you are taller than most, there is both an option for a regular size and long size. The long size fits up to 78 inches in length, while the normal 72 inches.

Portability
To allow for the easiest travel possible, Mountain Hardwear includes both a nylon compression sack and a mesh storage sack.

Overall
When assessing the Phantom Torch 3, it is difficult to answer the question of what is wrong? Honestly, past the tendency for the zipper to snag, you must dig very deep to come up with legitimate gripes against this sleeping bag.

Insulation
The Col has a crazy 44oz of 800 fill down that gives it an incredible loft and insulation. The warmth-to-weight ratio is great compared to many others on this list. The cut of the bag is wide to allow for many layers and movement.

Breathability
The zipper pull is glowing in the dark to help you see where it was snagged.

Comfort
The Col is great because of it's extra space that allows for a great deal of movement inside the bag. This makes it much more comfortable than other, more snug, bags on this list. One negative of the bag is the light-duty draft collar and thick material around the foot box that might not be the most comfortable. Again, you have multiple sizing options so if you happen to be taller or larger than others, you can select the size that adapts to you best.

Portability
With all the down and shell in this bag, it definitely makes for a larger pack size than some of the other bags on the list. However, it still packs down quite well considering its size and will fit inside a 60-liter pack and allow for other winter gear.

Overall
The Col is a great option for extremely cold weather. It is warm, weather-resistant, and comfortable. It has plenty of down to get you through those cold nights but won't weigh you down on your trek.

Insulation
The Ultralite features 850 down fill to keep you warm and properly insulates you evenly throughout the cold weather sleeping bag with the continuous and consistent baffles. The down collar wraps around your neck to maintain warmth.

Breathability
The shell is breathable and water-resistant, so you not only keep the cold out and toasty warmth in, but moisture should stay clearly at bay, too. The anti-snag zipper runs smoothly and goes almost all the way down to your feet. This allows you to get in and out of the sleeping bag easily, as well as open it if you’re feeling too warm.

Comfort
Reviewers are impressed with the overall comfort and warmth offered by the Ultralite 20. One thing to be careful of though is the width of the bag. If you have specifically wide shoulders, this may not be a comfortable fit for you.

Portability
Best of all, this bag is highly compressible, so you can easily pack it and ensure that you have enough room for everything else you need in your backpack.

Insulation
Much like Marmot, Teton integrates a different kind of insulation (SuperLoft Elite fiberfill) and innovative construction to keep you warm while eliminating cold spots. In addition, to fully maximize its 0-degree temperature rating, the zipper and shoulder draft tubes keep drafts from entering in.

Breathability
As this bag is designed for two people, there are plenty of zippers to allow for easy access and ventilation. You can unzip this beast from both the sides and the bottom.

Comfort
Truly noteworthy here is that the brushed flannel liner that is integrated into the inside of these cold-weather sleeping bags resembles the texture of bed sheets, making it comfortable to the touch. At 94 x 62 inches, this sleeping bag is enormous and is designed to fit more than one person.

Portability
Let’s get this out of the way, this is indeed a Mammoth as it clocks in at 16 pounds. Yes, there is an included Oxford compression sack. However, for backpacking, this is going to be extremely heavy.

Overall
To be honest, this is not the best sleeping bag for backpackers or anyone who plans on carrying their sleeping bag over long distances. Instead, this is ideal for individuals who are camping in the cold weather and looking for massive size.