Winter is a beautiful season that offers a lot to enjoy outdoors such as stunning snow-covered landscapes, tranquility, and all kinds of fun activities on the snow and ice. It also presents some harsh conditions to endure, especially at night when it gets extremely cold for long hours. Knowing the conditions you will likely encounter and packing the right gear is the key to enjoyable and safe winter adventures.
Especially for overnight and multi-day trips, it’s critical to pack the best winter sleeping bag made for below zero temperatures to prevent you from experiencing hypothermia and keep all your toes intact. With this in mind, we’ve found and reviewed the best below zero sleeping bags for you, so that you can make the best decision before heading out for your next winter adventure.
How To Choose A Winter Sleeping Bag – Buying Guide
A cold weather sleeping bag is a matter of life and death in extreme temperatures. When it is nighttime and temperatures plummet, the kind of sleeping bag you packed determines whether you will be cozy and safe or miserable and at risk of freezing. Because sleeping bags are long-term investments as they last for years, your decision on an extreme cold weather sleeping bag is even more important. Getting the right sleeping bag for winter requires careful consideration, and that’s why we’ve compiled the most critical criteria while choosing the best winter sleeping bag for your outdoor adventures.
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Sleeping bags are rated according to the lowest temperatures they are equipped to protect and keep campers warm. The stated ratings are usually the lower limit temperatures at which the bag keeps a person alive but not necessarily comfortable. As important as the temperature ratings are, they are only meant to give a rough idea as to the appropriateness of the bag for certain conditions and they aren’t always accurate. Regular sleeping bags are rated based on the EN 13537 standard, but this is not the case with cold weather and extreme cold weather sleeping bags.
Manufacturers test and rate their winter bags by having people sleep in cold rooms and monitoring the temperatures at which they stay warm. This means that the ratings are subjective. How cold or warm a person sleeps depends on their gender, age, weight, hydration level, how the sleeping bag fits, what sleepwear they have on, and whether they are using a sleeping pad or not.
We recommend researching night temperatures and conditions in your destination and picking a sleeping bag with a rating that is 10 to 15 degrees lower than the lowest temperatures you’re likely to encounter. This way, you’re covered if temperatures take an unexpected dip. If you get too warm, you can always unzip your bag for ventilation.
The shape of the sleeping bag you choose affects your level of warmth and comfort by maintaining the warm layer of air generated from your body inside the bag. It also prevents the cold air from getting into the bag. In most cases, the shape also affects the weight, packed size, and how easy it is to transport. While the most common shape is rectangular, there are also mummy shape bags that are contoured like the human body. The third shape is semi-rectangular, which combines aspects of rectangular and mummy shapes.
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The best winter camping sleeping bag shape for keeping warm is the mummy shape. It hugs your body so there is less space to heat. It heats up fast and stays warm well. The mummy hood and adjustable collar insulate the head and neck. When it comes to portability, the best cold weather sleeping bags for backpacking, hiking, or mountaineering come in mummy shapes as they are lightweight and pack into a small backpack easily.
A rectangular design, on the other hand, has too much space for your body to heat and is not efficient at maintaining warmth. However, the most comfortable shape to sleep in is rectangular as it is spacious. The form-fitting mummy shape can feel restrictive especially if you have a relaxed style of sleeping or toss and turn a lot. The semi-rectangular is the combination of a rectangular and mummy shape, offering the benefits of both while minimizing their weaknesses.
Below zero sleeping bags utilize insulating materials to form a barrier between your body and the cold on the outside. Down insulation is unbeatable when it comes to warmth and comfort. It is superior to synthetic insulation in many ways. It has an excellent warmth-to-weight ratio, compresses and packs well, and is long-lasting. Its downside is that it is expensive, requires careful maintenance, loses its insulating properties when wet, and dries slowly. Synthetic insulation on the other hand offers three advantages over down. It is more affordable, insulates well even in wet conditions, and requires minimal maintenance. However, it is heavy and doesn’t compress or pack well.
Down insulation is the best for winter activities such as backpacking, hiking, mountaineering where it is important to have the lightest and smallest sleeping bag without sacrificing warmth and comfort. If you’re an avid winter adventurer and want to invest in a high-quality sleeping bag, down with the highest down fill power is your best option. It will cost you more but will serve you for a long time as long as you take proper care of it. If you’re on a tight budget, synthetic insulation will suffice.
The best lightweight winter sleeping bags also have features like draft collars, draft tubes, zipper guards, baffles, and adjustable hoods. These provide extra insulation and prevent cold spots.
Shell and Lining
The shell is the outer fabric, which is exposed to harsh conditions, therefore should be durable. Ensure that the shell is tough, breathable, and has a water repellent treatment to prevent moisture from seeping into the insulating layer. The lining, on the other hand, is the material on the inside of the sleeping bag. It should feel soft, warm, and comfortable on the skin while having moisture-wicking properties to assist in wicking away perspiration so that you don’t get too toasty and sweaty in the bag.
No matter how well your body is insulated, you won’t feel warm and comfortable if your head isn’t well insulated, thus making it a must-have feature in a sleeping bag. You want a well-insulated and adjustable hood to personalize the fit around your head to seal all gaps. You should also be able to retain enough moving space to fall asleep. It should also be able to handle water vapor from your breathing or be designed in such a way that you’re not exhaling into it.
Stash pockets on the inside of a cold-weather sleeping bag come in handy when you want to keep valuables such as electronics within reach. If you find a sleeping bag that has all the qualities you need in below zero temperatures and also has a pocket on the inside, then you’ve got a winner.
Sleeping Pad Sleeve
A winter sleeping pad acts as an extra insulating barrier between your bag and the frozen ground. In this way, the ground doesn’t steal your body heat and you don’t find yourself waking up in the middle of the night feeling cold. A sleeping bag with a sleeping pad sleeve (a pocket underneath the bag that you insert the sleeping pad into) also prevents you from rolling off the pad during sleep.
For most people, a pillow is essential for comfortable sleep. In addition to comfort, when sleeping outdoors in the winter, it is another barrier between your head and the frozen ground. A sleeping bag with a pillow pocket gives you the option of inserting your pillow of choice, too. You can also stash your clothing to make a pillow and save some space. The bonus is that you will wake up warm and have warm clothing to slip into!
Sleeping bags are bulky and always a challenge to pack with limited space and that’s why an effective stuff sack with compression straps is a critical sleeping bag accessory. It makes it easy to compress the sleeping bag into a compact and portable packed size giving you the option to attach it to your pack without taking up much space. Most sleeping bags come with a stuff sack however it is a bit tricky to stuff them into the sack. We recommend you read user reviews to find out how to compress the fluffy sleeping bag and get it inside the compact stuff sack. Buying your spacious compression sack separately is also an option.
To ensure your sleeping bag lasts longer and continues to keep you warm, you must store it properly. Keeping it in the stuff sucked in a compressed form for a long time is a no-no because the insulating filling will break down, lose loft, and lose its efficiency. You need a spacious storage sack so that you can store it in a loose form to preserve the quality of insulation as well as the shelf life of your sleeping bag.
A liner adds to the warmth and comfort level you experience inside the bag. It also prolongs the life of your sleeping bag by protecting it from body oils, sweat, and cosmetics. The best winter sleeping bag has its liner and saves you from the trouble of purchasing another liner separately.
A lightweight sleeping bag that doesn’t compromise on warmth and comfort is the best winter backpacking sleeping bag for activities like hiking and mountaineering. Finding a sleeping bag that achieves this balance is important but tricky, as the cheapest below zero sleeping bags tend to be the heaviest while the lightest and warmest are the most expensive.
Down sleeping bags are the best winter backpacking sleeping bags because of their fantastic warmth to weight ratio. They provide warmth even in the coldest conditions while still managing to stay lightweight. They have higher price tags but are also long-lasting, which makes them a worthy investment in the long run especially if you’re an avid mountaineer or winter adventurer.
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Durability is determined by the kind of materials used in a bag’s construction. A tough, ripstop outer shell material that can stand up to harsh weather elements and abrasion is essential for durability. The zippers should also be strong and snag-free, so they slide smoothly. As for insulation, synthetic is more durable than down fill, but down fill performs better in cold conditions. Also, remember that proper maintenance and storage also prolongs the life of a bag.
Q: Why does a down-filled sleeping bag keep you warm on a cold night?
A down-filled bag has a thin and fine layer of bird feathers which is famous for its insulation properties. With the thin texture and structure of down-filled sleeping bags, the naturally generated body heat of the user gets trapped and transferred in the sleeping bag. By capturing your body heat, a down-filled sleeping keeps you warm.
Q: What sleeping bag do I need for winter camping?
To survive the chilly nights during winter camping, it is recommended that you get a sleeping bag that is at least 10F lower than the coldest temperature range. Additionally, choose a bag that has synthetic insulation. The sleeping bag must have high-quality draft tubes and collars to keep the cold air out. Just as a precaution, you can add a sleeping bag liner to protect yourself from extremely cold climates.
Q: Is it warmer to sleep with clothes on or off in a sleeping bag?
Wearing the right type of clothes will indeed act as an extra layer and give you extra insulation. However, avoid wearing tight clothes as they will cause a problem in your blood circulation, making you feel cold. Similarly, wearing moist clothes or extra thick clothes will make you sweat more, making you more prone to catching a cold.
Q: How can I increase the warmth of my sleeping bag?
Using sleeping bags for a long duration weakens the insulative filling. A good way to restore it to its original quality is by washing it. If you wash it after a long trip, then the overall quality of the bag will improve and its warmth-trapping qualities will be retained.
Q: What do I need to know about water resistance before buying a sleeping bag?
The first thing you need to know about water resistance before buying a sleeping bag is that a sleeping bag loses its insulating properties if it becomes wet.
Different types of sleeping bag insulations have different water resistance properties. Synthetic materials have some water resistance properties, dry fast, and perform best in wet conditions. Down soaks in moisture readily, takes longer to dry, and loses its insulating properties when wet.
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It is important to check if the outer material has a Durable Water Repellent (DWR) finish to make water bead up and roll off the shell rather than soak through. Hydrophobic down is down-treated with polymers to improve its water resistance and drying properties.
Let's also mention that water-resistant does not mean fully waterproof. There is no completely waterproof down sleeping bag or synthetic bag. Water-resistance is the ability to resist light splashes, condensation, and low moisture levels. A lot of moisture or prolonged exposure to damp conditions will cause the sleeping bag to take on water.
The most effective way to ensure your sleeping bag stays dry is to ensure that your sleeping bag doesn’t come into contact with moisture in the first place. The first line of defense against moisture is to use a ground tarp so your sleeping bag is not in contact with the ground.
Q: How should I store my sleeping bag?
First, ensure it is completely dry by hanging it to air dry. Store it in a cool, dry place in a loose form. You can hang it in a closet or fold it loosely like a blanket and store it on a shelf without anything on top compressing it. You can also keep it in a spacious storage sack, where it isn’t compressed. Storing it in a compressed form causes the filling to break down and lose its insulating properties.
Q: How should I wash my synthetic sleeping bag?
One of the advantages of synthetic sleeping bags over down bags is that they are easier to wash. Most synthetic bags are machine washable. Hanging them to dry is best but some can also be thrown in the dryer. However, the washing, detergent, and drying temperature requirements vary from manufacturer to manufacturer. We recommend checking the manufacturer’s tag and following the instructions and recommendations.
Q: How does the foot box on a sleeping bag work?
Sleeping with your feet pressed tightly together and immobile would be uncomfortable or impossible. The foot box on a sleeping bag provides space so your feet have freedom of movement when you’re sleeping inside the bag.
Q: What should I know about zippers before buying a sleeping bag?
Zippers can be weak areas that let in cold air or break easily because of how frequently they are used. Ensure the bag you get has strong, heavy-duty zippers equipped with zipper guards and an anti-snag design, so they open and close smoothly without catching the bag’s material. A two-way zipper that allows you to open from the top or bottom is great as you can open the bottom area for ventilation if it gets too warm and stuffy inside the bag. To seal the tiny zipper gaps, the best below zero sleeping bags have insulation baffles above and below the zipper.
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From skiing, fishing, and mountain climbing to hiking, backpacking, and camping, there are plenty of fun activities to enjoy in the winter and the kind of sleeping bag you have can make or break the whole experience. We hope our cold weather sleeping bag reviews and buying guide have given you a better idea of which bag will best suit your needs. The bags on our list are some of the best winter camping sleeping bags available on the market and great for hikers, campers, and backpackers alike.
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Which of the below zero sleeping bags on our list is your top choice? We would love to read your thoughts or experience with the cold weather sleeping bags we’ve reviewed! Feel free to share in the comment box below!