When purchasing a sleeping bag, it is important to consider the climate and season in which you most often camp. If you live in the rainy pacific northwest, you will want a bag that can withstand rain and moisture. If you often travel in the shoulder seasons of spring and fall, then you will want to purchase a three-season bag that will keep you warm in a range of temperatures and weather. And if you only camp in the summer (as a majority of people do) and you stick to lower elevations and warmer regions, then you can get away with a lighter, less warm summer bag. Often, people will purchase multiple sleeping bags, one appropriate for each of these scenarios.
The summer sleeping bag category is an interesting one: focused on bags rated for 30ºF or higher, these products can be extremely lightweight. Manufacturers have begun to develop non-traditional shapes with options meant to increase ventilation and comfort while reducing weight. Sometimes new technology can be gimmicky or just plain strange, so we wanted to asses what is just marketing and what actually works. With this in mind, we chose to review both standard mummy-style summer sleeping bags as well as non-traditional models. Our aim was to include both down models and high-end synthetic options so that readers can make the most informed choices about what will best suit their needs. Our resulting selection provides a cross-section of the best lightweight summer sleeping bags on the market.
After hours of research and numerous emails quizzing companies about their premier products, we settled on seven ideal test models. Then we tested these sleeping bags through a summer of adventures. We went backpacking in the High Sierra in California and the Wind River Range in Wyoming, car-camped at campgrounds at both high and low elevations to experience different nighttime temperatures, and cowboy-camped in Oregon national forest where we could see the stars through the trees. More than six different testers of varying ages, genders, and skill ranges tried out these bags and provided feedback and opinions, which you can read in our complete review below.
The Feathered Friends Flicker YF 30 is hands-down our favorite summer sleeping bag. It transitions from a well-ventilated open quilt in warmer weather to a tube-style sleeping bag (albeit without a hood) when the temperature drops. In addition to being versatile, it is warmer, lighter, and more compressible than any of the other 30F rated bags in our test. And to polish off this well-designed product is the YFuse Pertex Quantum face material, which is more down-proof and water resistant than most other fabrics, meaning that this bag is likely to last a while.
The Sierra Designs Cloud 800 is a unique zipperless bag. Instead of a typical side-zip, it has a blanket fold on the front that tucks around a sleeper and keeps them warm. The fold can be tossed aside for more airflow in warmer temperatures. Rated for 35 degree nights and weighing 1 lb 7 oz, this bag was a top contender in our summer sleeping bag test. Ultimately, we think the Cloud is an excellent choice for someone in the market for a lightweight summer bag, but who doesn’t want to throw down the cash for an expensive Feathered Friends bag.
The Nemo Ramsey 30 is a fairly standard summer sleeping bag filled with features. To our surprise, we love the blanket fold draft collar which tucks in around the chin and neck for cozy comfort. Thermo gill vents and a full-length zipper allow for easy ventilation if the weather is warm, the stash pocket provides a convenient place to store a headlamp or a contact case, and waterproof/breathable material on the hood and footbox protect from condensation and weather. All of this adds up to one of the heaviest bags in our summer sleeping bag review, but this is still an excellent option for those who prioritize comfort.
For someone in the market for the smallest, lightest, and simplest bag to take on fast-and-light summer adventures, the Therm-a-Rest Space Cowboy is the perfect product. Very simple in design, it lacks any extra features besides the ability to connect to a sleeping pad. This synthetic bag is extremely thin; it is rated for 45ºF at its limit but is comfortable at 52ºF. This means that the Space Cowboy is only adequate in very warm temperatures. However, because of its simplicity and thin insulation, it is the lightest bag in our summer test and it packs very small: perfect for fast bikepacking or backpacking adventures in hot weather.
When camping in wet weather, a synthetic insulated sleeping bag provides a safer bet than down because it continues to insulate when wet. The Marmot Ultra Elite 30 proved to be one of the lightest and smallest synthetic bags on the market. Its simple design keeps the weight down and the included compression sack stuffs the bag into a small package. While heavier and less compressible than down alternatives, the Ultra Elite is our choice for rainy summer camping and backpacking.
For the purposes of this review, we have defined summer sleeping bags as any bag rated for 30º Fahrenheit or warmer. Companies determine the temperature ranges of their bags using different methods, but we used this basic benchmark of a 30-degree rating for determining if a bag should be included in our test.
When assessing these warm weather bags, we found that weight and compressibility were our primary concerns. We wanted lightweight bags that packed small. As with any sleeping bag, it was important for it to keep us warm while sleeping, but unique to the summer category we realized that the ability to ventilate is also important. If the night is hot and humid, it is necessary to dump hot air and let in refreshing breezes. Lastly, we asses the features of each bag—some of which make the bags exceptional—and we speculate on the durability of each product. All of these metrics, when taken together, give us a fairly complete picture of how well each product performs.
Summer sleeping bags are a unique corner of the sleeping bag market. Since they are designed for warm weather, they have less insulation inside, which allows them to be much lighter than bags designed for colder temperatures. Many companies have begun to experiment with the design of their bags to make them more versatile, more comfortable, and ultralight. For this round of testing, we solicited a combination of classic mummy-style bags and bags with non-traditional designs and shapes. After sleeping in these bags in a variety of environments, temperatures, and conditions, we have found that the non-traditional bags often strike an improved balance between warmth, weight, and ventilation. We predict that companies will continue to innovate and develop new styles of sleeping bags in the future, in particular in this summer weight category.
Often, the weight of the sleeping bag decreases as the temperature rating increases. The bags rated for higher temperatures require less insulation, which equals less weight. The lightest weight bag in this lightweight category is the Therm-a-Rest Space Cowboy, which is the thinnest and least warm bag in this review. The Space Cowboy is rated for 45-degrees and it weighs 1 pound 3 ounces. Tied for second in terms of weight are the Feathered Friends Flicker and the Sierra Designs Cloud 35 at 1 lb, 7 oz. If you assess the warmth-to-weight ratio, the Flicker wins hands-down: it is rated for the coolest weather (30ºF) and is much loftier than either the Space Cowboy or the Cloud. One of the primary reasons that the Flicker wins our Best in Class award is this high warmth-to-weight ratio. We would rather carry a product that keeps us warmer for the least amount of effort.
For an initial rough comparison of compressibility, we stuffed each bag into its included stuff sack and compared the size of the resultant package. However, this is misleading. Some of the bags came with sacks that included compression straps and some did not. Those with proper compression sacks end up smaller. Some of the bags that did not come with compression sacks, such as the Feathered Friends Flicker, can actually compress much smaller in a different sack.
The primary determining factor in the bags’ compressibility is the quality of the insulation. Higher quality down packs down smaller and tighter than low quality down, and down usually compresses better than synthetic insulation. The Feathered Friends Flicker has the highest quality down with 900+ fill power and we found it to compress the best. Next is the Sierra Designs Cloud with 800-fill. The rest of the down bags had 650-fill down, and the Therm-a-Rest Space Cowboy and the Marmot Ultra Elite both have synthetic insulation. Both of these packed down remarkably small.
In a sleeping bag designed for warm weather, an important feature is the ability to ventilate. If it is hot and sticky, a sleeper will want to be able to get some fresh airflow. The classic mummy-style sleeping bags (Therm-a-Rest Space Cowboy, Big Agnes Wiley, and Marmot Ultra Elite) have no ventilation feature other than the side-zipper. This does allow the bag to be opened and the top of the bag to be folded to the side. The Nemo Ramsey, which is also a classic mummy bag, has the addition of Thermo Gills. These are uninsulated pockets along the top of the bag that unzips to help dump hot air without letting in drafts. The zipperless Sierra Design Cloud closes on top with a fold-over blanket-like flap, and this allows for excellent ventilation because it can be tossed aside like a blanket. There is also a flap in the footbox so feet can extend out the end of the bag if they are too hot inside the bag.
The two best-ventilated bags in this test are the ones that can convert to quilts, The North Face Campforter and the Feathered Friends Flicker. In the case of the Campforter, the top of the bag zips off to become a camp blanket. In hot conditions, the bottom of the bag can be stored and just this light blanket could be used, which allows for plenty of airflow along the sides. Likewise, the Flicker has a full-length center zip that can be undone so that the whole bag folds flat like a quilt. The bag can be used in this mode when it is hot, providing plenty of ventilation and freedom of movement.
Just as the ability to ventilate in hot weather is important, a summer sleeping bag should also keep you warm when the nights get chilly. Since this is the summer bag category, none of the products in this review are going to be adequate for winter conditions, but we did find that some were better for chilly high altitude nights than others. The warmest was by far the plush and lofty Feathered Friends Flicker. Even without a hood, this bag is coziest, and the one that we preferred to bring on backpacking trips into the mountains. When using this bag, to prevent the head from getting cold, we suggest sleeping in a beanie, Buff, or a fleece with a hood, like a Patagonia R1. Close behind the Flicker are the other 30-degree bags with more classic designs. The Big Agnes Wiley, Nemo Ramsey, and Marmot Ultra Elite all have hoods and draft collars which help seal in warmth. We especially love the Blanket Fold draft collar on the Ramsey, which we feel increases coziness and warmth more than a tube-style draft collar.
The North Face Campforter and the Sierra Designs Cloud are both rated to 35 degrees, which is slightly hotter weather than the previously mentioned bags. We found that these were indeed slightly less warm than the bags we tested that were rated to 30 degrees. The Cloud is thinner and less lofty, but the fold over closure does a good job of keeping body heat inside the bag when necessary. The Campforter proved roomy and comfortable when zipped together in mummy mode. If the top part of the bag is zipped off, it works as a camp blanket, which helps add warmth when just hanging around the campfire or picnic table.
The least warm bag in this review is the Therm-a-Rest Space Cowboy, which is rated to 45 degrees. However, we noticed that 45 degrees rating proved to be the true EN limit rating for this bag, and the comfort rating is 52 degrees. This bag is incredibly thin and lightweight, so we only recommend using it in low elevation, very warm conditions. In this situation, it is perfect because it requires a person to carry the exact amount of insulation that is needed but do not expect this bag to keep you warm on a cool night in the mountains.
The features and design is the metric that really begins to distinguish some of these sleeping bags from the others. The bags in this review fall into two main categories: classic mummy-style bags and non-traditional bags. For the classic mummy bags, we have the Marmot Ultra Elite, Therm-a-Rest Space Cowboy, Nemo Ramsey, Big Agnes Wiley. All of these bags have a standard shape that is narrower at the feet and wider at the shoulders, a cinchable hood, some type of draft collar, and a three-quarters length or more side zipper. This style of bag has an excellent warmth-to-weight ratio and the shape efficiently eliminates dead air pockets that can make people colder. Small details set some of these bags apart: the Ramsey and the Ultra Elite both have small stash pockets. The Wiley has a vaulted, roomier footbox. The Ramsey has a Blanket Fld draft collar that is extra large and reminiscent of a blanket, which we find to be comfortable and cozy. The Ramsey also has Thermo Gills, which help to ventilate the sleeper in warm weather.
Most of the bags in this test have some way of attaching the sleeping bag to a camping mattress. This is either in the form of separate attachments, sleeves, or using the storage sack to attach around the sleeping pad.Then there are the non-traditional bags which break from the mummy shape and style in various ways. Each of these products deserves some mention and explanation of their own. First is the Sierra Designs Cloud. This bag has been designed to be zipperless, which cuts down on weight and bulk. It still has a classic mummy shape with a hood, but instead of a side zipper, there is a crescent-shaped opening on the top of the bag with an attached blanket-like flap that folds over to enclose the sleeper. This flap has a pocket that securely fits onto the sleeper’s shoulder to keep the bag closed. There is also a flap in the footbox for feet to poke out for fresh air, or to allow the bag to be worn around camp. This design is unique, roomy, and comfortable, especially for people who feel too confined in a standard mummy bag. Next, there is The North Face Campforter. This bag looks like a standard mummy bag, but with extra room. It has a boxy shape and a large hood. The top of the bag has a full circumference zipper so that the top half of the bag can be removed completely and used as a camp blanket. The bottom half of the bag has synthetic insulation and the top half is down. This design allows for more versatility beyond what a standard sleeping bag accomplishes. We found that we used the camp blanket frequently, and we loved this feature. Finally, the Feathered Friends Flicker. This is a hoodless bag that transforms into a quilt. It has a full-length zipper, that when undone, allows the bag to fold flat into a quilt. If it is cold and the sleeper prefers to be wrapped in standard-sleeping-bag-comfort, the bag can be zipped together and the footbox can be closed with a drawcord. This design allows for a lot of flexibility in terms of weather and sleep position. Particularly for a summer weight bag, we think the ability to transition from bag shape to blanket shape is a huge advantage.
Since we did not have any catastrophic accidents with any of the bags in this test, durability was a little difficult to measure. It would have been easy to rank if some of the bags had failed, but all of the products withstood the rigors of regular camping and backpacking. So to score durability, we have to evaluate other features and go out on a limb somewhat to predict how the products will continue to perform throughout their lifetime. To make this prediction, we examined the denier of the fabrics used in the construction of each bag.
Denier is a measurement of the linear density of fibers. Higher numbers indicate more dense fibers for a given length. Denier provides some indication of durability, but thread count and weave pattern also affect the sturdiness of a product. Usually, a higher denier also means higher weight, so lightweight products often use low denier fabrics to achieve light overall weight. In this test, most of the bags feature a 20-denier nylon. There are 2 exceptions: the Sierra Designs Cloud uses lighter 15-denier fabrics and the Nemo Ramsey uses thicker 30-denier fabrics with 40D water resistant material on both the hood and footbox. We think this gives the Ramsey a slight edge in durability over the rest of the bags.
And finally, in our durability assessment, we consider insulation type. Down is more durable over the long-term than synthetic insulation: it can handle more compressions and expansions and will in general last longer. A well-made down bag will outlast a synthetic bag by years. However, synthetic bags are more durable in the short-term. Bags insulated with down are vulnerable to rips and tears. If a hole appears in the fabric, the feathers spill out and the bag becomes useless. Synthetic bags have the benefit of being able to withstand rips and tears; the insulation will not fall out. So for rough use and situations where a sleeping bag may endure some abrasion or contact with sharp objects, a synthetic bag is most reliable.
Here at Gear Institute, we firmly believe that the best way to test and compare gear is to use it. Some very important features, like comfort, cannot be reflected in manufacturer specs. So use them we did. We handed sleeping bags out to over 6 different testers of varying age, gender, and ability and asked for their opinions. Bags were used on backpacking trips, climbing trips, in campgrounds near the car, and to sleep on friend’s floors. We used them at low elevations and high elevations, on cool nights and warm nights, in tents and directly on the ground. By trying each bag in different weather and conditions we were able to test for both warmth and ventilation, and asses what works and what doesn’t in each product.
Some metrics involve a closer assessment than simply using and offering an opinion. Even the metrics that are mostly subjective, such as warmth, were backed up by research. In the case of warmth, we looked at the insulation type and fill weight to note how well each bag was insulated.
To compare compressibility we stuffed each bag into its included sack and compared the sizes. Then, to be more objective, we stuffed each bag into the same stuff sack to see how well each one packed in the same size container. To rank weight, we weighed each bag on our own scale. To score for durability we compared the denier of the materials used to construct the bags.
We were then able to cross-reference our tester’s thoughts with the specs from each bag to come up with a score that reflects both our subjective opinions of each sleeping bag and the objective data points.
What is a Summer Sleeping Bag?
We define a summer sleeping bag as a bag rated for 30ºF or warmer. This means that the bags within this category are lightweight and have less insulation than warmer bags. Unique to this category is the importance of ventilation. Since summer bags are often used in hot weather, the bags need to be warm enough for cool nights but also need to have the ability to let in cool air when the nights are hot and humid. Within this category of summer bags, we there are a few smaller categories included in this review.
In this review, we included bags of both insulation types.
Down bags are insulated with down feathers, usually from geese. Down has the advantage of a high warmth-to-weight ratio and it compresses extremely well. Down is also durable enough to handle years of use and still perform well. Down’s primary weakness is that if it gets wet, the feathers clump together and lose their insulating properties. Nowadays many manufacturers treat their down with a water resistant coating to allow the down to hold up to dew, frost, condensation, and light moisture better. Down insulated products are also vulnerable to tears. A hole in the face fabric allows the insulation to leak out.
Synthetic insulation is composed of man-made fibers. There are numerous brands of synthetic insulation on the market. Though synthetic insulation has yet to achieve the warmth-to-weight ratio and high compressibility of down, it is getting better all the time. Synthetic insulation’s primary benefit is that it maintains its insulating properties when wet, so a synthetic sleeping bag is the best choice if camping in rainy weather. Synthetic insulation wears out after too many compressions and expansions, so a synthetic product will never last as long as a down product, but in the short-term, this insulation is more durable against abrasion and rips.
When researching summer bags we found that while there are many bags designed in the classic, familiar mummy shape, companies are experimenting with non-traditional shapes and features. We included examples of both in this review.
Classic mummy bags
The classic mummy bag has a tapered shape that is wider at the shoulders and narrower at the feet. This design is to reduce weight and reduce cold spots within the bag. Most mummy bags have a three-quarters length zipper down one side, a hood with a cinch, and a draft collar to keep warm air in around the neck and shoulders. This style of bag has proven to be one of the most efficient shapes for a sleeping bag, but many users feel this design is too confining and uncomfortable.
We define non-traditional bags as anything that breaks with the mummy bag tradition. This includes quilts, zipperless bags, hoodless bags, bags that mimic beds, and bags that convert from one shape to another. More and more companies are developing non-traditional bags because they are can be more comfortable, can be lighter weight, and the new innovations can increase versatility.