6 Warmest Sleeping Bags of 2024

By Bryan ListorLast update: 2024-01-23

Picking out the warmest sleeping bag for your needs is no easy task.

But worry-free! With skillful experience and many expert friends in this field, we’ve analyzed and rounded up to this list of 6 top-rated options. Take a look!

Here are the warmest sleeping bags (Mar 2024 Update):

  • Down - Warmest Model: Hyke & Byke Eolus
  • Down - Runner-Up: Outdoor Vitals Down Sleeping Bag
  • Down - Best For Folks: Klymit KSB
  • Synthetic - Warmest Model: TETON Sports Deer Hunter Sleeping Bag
  • Synthetic - Best For Couples: TETON Sports Mammoth Queen-Size Double Sleeping Bag
  • Synthetic - Best For Backpackers: Suisse Sport Everest Sleeping Bag
Top 6 Warmest Sleeping Bags
Down - Warmest Model
Hyke & Byke Eolus
    Read Our Review
    Down - Runner-Up
    Outdoor Vitals Down Sleeping Bag
      Read Our Review
      Down - Best For Folks
      Klymit KSB
        Read Our Review
        Synthetic - Warmest Model
        TETON Sports Deer Hunter Sleeping Bag
          Read Our Review
          Synthetic - Best For Couples
          TETON Sports Mammoth Queen-Size Double Sleeping Bag
            Read Our Review
            Synthetic - Best For Backpackers
            Suisse Sport Everest Sleeping Bag
              Read Our Review

              Warmest Model: Hyke & Byke Eolus

              Down
              Top Pick
              Hyke & Byke Eolus
              Hyke & Byke Eolus
              Pros
              • Third party tested and IDFL Certified to ensure quality and humaneness

              • Most compact packed size of this list for optimal portability

              • Use microscopic air clusters for decent loft and warmth

              Cons
              • Unpleasant smell

              • Too much puffy

              The most versatile in my list is Eolus with emphasis on three different length options, small pack size (of 10” x 7”), and lightweight 3.4-pound weight.

              I love 4-point compression straps in the sack. They actually are connected quick-release black thermoplastic buckles and HD black nylon webbing that help me to pack down the bag effortlessly and easily.

              Hyke & Byke is a reliable outdoor-gear brand so I really rest assured of their products’ down quality.

              It is the premium goose down 800 fill power that is hydrophobic and more importantly, IDFL Certified to ensure bird feathers aren’t lively plucked.

              The microscopic air clusters in this down bag are notable. They increase the volume/loft of the unit to lock and provide adequate warmth for all seasons.

              Lined with 400T Rip-Stop Nylon Fabric and zipped by double large YKK anti-snag zippers, Eolus is also well-loved for its durability and longevity.

              Hyke & Byke Eolus Specifications

              Temperature Rating

              0°F

              Dimensions

              Short: 72" x 26"

              Regular: 78" x 28"

              Long: 87" x 32"

              Packed Size

              10" long and 7" in diameter

              Shape

              Mummy

              Recommended Height

              Short: 5'-6" tall

              Regular: 5’-7” to 6'-1" tall

              Long: 6'-2" to 6'-6" tall

              Weight

              Short: 3.02 lbs.

              Regular: 3.20 lbs.

              Long: 3.37 lbs.

              Machine Washable

              No

              Highlight Feature

              Light and compact, long-lasting durability
              Microscopic air clusters, IDFL Certified

              Overall, if you’re looking for a perfect warm sleeping bag to camp out in any season with decent warmth and comfort, I’m sure Eolus fits the bill.

              Runner-Up: Outdoor Vitals Down Sleeping Bag

              Down
              Outdoor Vitals Down Sleeping Bag
              Outdoor Vitals Down Sleeping Bag
              Pros
              • The lightest sleeping bag in this list

              • Water-repellent shell, liner and hydrophobic fill power for lower maintenance and keep you dry

              • 4-point compression bag for easier packing it down when not in use

              Cons
              • Not durable compression sack

              The tighter fitting Outdoor Vitals Down Sleeping Bag with the extended hip area and narrower shoulder width is the best bet for women.

              Like the Hyke and Byke Eolus, is the hydrophobic 800-fill power (IDFL tested) down, three different length options, and 0°F of temperature rating.

              What pull it down to the No.2 position of this list are pack size and lining material (only 20D ripstop nylon). In turns, it’s lighter and more affordable.

              The shell of this bag highlights VitalDry DWR feature which actually is a water-repellent coating to keep you stay dry inside. And the baffle shape allows for relocating some down from the back area to the foot box for extra warmth.

              Outdoor Vitals Down Sleeping Bag Specifications

              Temperature Rating

              0°F

              Dimensions

              Short: 69 x 31 inches

              Regular: 75 x 31 inches

              Long: 81 x 34 inches

              Packed Size

              14 x 8 x 8 inches

              Shape

              Mummy

              Recommended Height

              Short: 5' 6"

              Regular: 5' 6"

              Long: 6' - 6' 6"

              Weight

              Short: 2 lbs. 11 oz

              Regular: 2 lbs. 12 oz

              Long: 2 lbs. 15 oz

              Machine Washable

              No

              Highlight Feature

              Lightweight, warmer feet
              Includes 4 point compression bag, water resistant

              All-in-all, cold sleepers who have smaller body size and are in a tight budget, you shouldn’t overlook at this sleeping bag.

              Best For Folks: Klymit KSB

              Down
              Klymit KSB
              Klymit KSB
              Pros
              • Give more chest space for more comfortable moving inside

              • Provide extra warmth to face, head, and feet.

              • Stash pocket to keep small items warm with you

              Cons
              • Heaviest compared to other down units in this list

              • A bit snug at shoulders

              With Klymit KSB, I found the wide cut stands out from other down sleeping bags, which a 5’ 3” or shorter folks can even change clothes inside it.

              By providing more chest area, it can accommodate some extra layers of clothes put on you for more warmth. The sleeping bag itself is also equipped with insulated mummy hood and draft collar to keep your head, face, and neck cozy.

              If you feel the down volume in the back area isn’t necessarily that much, its baffle design lets you flexibly relocate them to the foot box or anywhere you need more warmth.

              Plus, there is a stash pocket where you can keep some small items together inside the bag, such as a smartphone, book, water bottle, and wallets.

              Compared between such huge benefits and high-quality 650 fill-power white duck down, I feel the price is worthy.

              Klymit KSB Specifications

              Temperature Rating

              0°F

              Dimensions

              82 x 40 x 1 inches

              Packed Size

              15” x 7.5”

              Shape

              Mummy

              Recommended Height

              5’ 3”

              Weight

              3.9 lbs.

              Machine Washable

              No

              Highlight Feature

              A draft collar, over-stuffed foot box
              Expanded chest area, insulated mummy hood, and flexible baffles

              It’s particularly suited for short, cold sleepers who love sleeping nice and toasty on frostbite nights outdoors with more room to move.

              Warmest Model: TETON Sports Deer Hunter Sleeping Bag

              Synthetic
              TETON Sports Deer Hunter Sleeping Bag
              TETON Sports Deer Hunter Sleeping Bag
              Pros
              • Reduce compression and distribute fill evenly to avoid chilly spots

              • Keep drafts out easily

              • Can connect to another TETON sleeping bag to share sleeping space

              Cons
              • No zipper on the opposite side

              Despite a synthetic sleeping bag, I don’t find TETON Sports Deer Hunter inferior to other down units in terms of warmth.

              It stands out with the innovative SuperLoft Elite 4-Channel Hollow Fiber Fill that’s not only rated to below freezing temperatures. Also, a combo of staggered seams and zipper baffle for better fill distribution and less chilly spots.

              For extra warmth, a mummy-style hood comes into place and a padded drawstring opening keep drafts out.

              Targeted for deer hunters whose wears and tears will apply on the bag, the shell and liner are enhanced for durability. It’s also wrapped into a heavy-duty duffle bag for extra protection.

              TETON Sports Deer Hunter Sleeping Bag Specifications

              Temperature Rating (degree)

              0°F

              Dimensions (inch)

              90” x 39”

              Packed Size (inch)

              38" x 9.5" x 9.5"

              Shape

              Rectangular

              Recommended Height

              7’

              Weight (lb.)

              8.5 lbs.

              Machine Washable

              Yes

              Highlight Feature

              Spacious, zipper baffle and padded drawstring opening
              Staggered seams, heavy-duty duffle bag included

              For bigger adults of 7 feet tall, searching for a spacious, ultra-warm, and lightweight synthetic sleeping bag, TETON Deer Hunter is a perfect go-to.

              Best For Couples: TETON Sports Mammoth Queen-Size Double Sleeping Bag

              Synthetic
              TETON Sports Mammoth Queen-Size Double Sleeping Bag
              TETON Sports Mammoth Queen-Size Double Sleeping Bag
              Pros
              • Soft, comfortable, and skin-friendly

              • Easy access on each side and the bottom

              • Keep heat in for maximum warmth

              Cons
              • Hard to stuff into the compression bag

              While being much larger - 94 x 62 inches size, the TETON Sports Mammoth is uniquely made for thermal enhancement to prevent two sleepers from freezing.

              It highlights a double layer offset stitch construction, hollow fibers trap air, and zipper and shoulder draft tube for maximum warmth.

              At the meantime, is the extended length and width (compared to other queen-sized sleeping bags) for ultimate comfort.

              Though I have to wear a beanie, still appreciate its half-circle mummy hood that keeps my head off the ground.

              If you’re a cold sleeper with sensitive skin, rest assured to try Mammoth as both its synthetic SuperLoft Elite fill power and Taffeta shell fabric are non-allergenic.

              TETON Sports Mammoth Queen-Size Double Sleeping Bag Specifications

              Temperature Rating

              0°F

              Dimensions

              94 x 62 inches

              Packed Size

              28" x 15.75" x 15.75"

              Shape

              Rectangular

              Recommended Height

              7’

              Weight

              16.5 lbs.

              Machine Washable

              Yes

              Highlight Feature

              Soft poly-flannel lining, zipper and shoulder draft tubes
              Hollow Fibers Trap Air, Non-Allergenic

              Constructed as a queen-sized sleeping bag with fill power and extra-warm poly-flannel lining, this TETON is really ideal for couples.

              Best For Backpackers: Suisse Sport Everest Sleeping Bag

              Synthetic
              Suisse Sport Everest Sleeping Bag
              Suisse Sport Everest Sleeping Bag
              Pros
              • Micro Tack Z1 fill to lock lots of air for maximum warmth

              • The lightest of three synthetic sleeping bags

              • Soft insulating layer in the mummy hood to keep you breathe freely

              Cons
              • Weak drawstring

              • A bit flimsy zipper

              For those who are looking for maximum thermal efficiency, there is the Suisse Sport Everest – also the lightest of three synthetic sleeping bags in this list. It packs 3.5 pounds of Hollowblend MicroTekk Z1 synthetic fill into a 19” x 12” package.

              Similar temperature rating but the Everest feels warmer to the chest than two previous TETON because it’s equipped with full chest baffle.

              Combined with a draft tube and double-layer offset quilt construction, the sleeping bag prevents drafts out while eliminating cold spots decently.

              The mummy hood is also worth mentioning. It stands out with a soft insulating layer that not only covers your head and shoulders better but also allows you to freely breathe.

              Suisse Sport Everest Sleeping Bag Specifications

              Temperature Rating

              0°F

              Dimensions

              84 x 24 x 33 inches

              Packed Size

              19 x 12 x 10.9 inches

              Shape

              Semi-Rectangular

              Recommended Height

              6’

              Weight

              4.85 lbs.

              Machine Washable

              Yes

              Highlight Feature

              Puffy double-layer construction
              Full chest baffle prevents drafts

              Lightweight, comfortable, ultra-warm, and compact, the Suisse Sport Everest is highly recommended for backpackers and travelers.

              How To Choose A Warm Sleeping Bags?

              A sleeping bag’s warmth is influenced by a combination of fill material’s volume and shape.

              Fill Material’s Volume

              • There’s a basic rule of thumb: The more loft the bag has, the warmer you have.

              • The reason for that is more volume of fill material creates more air insulation between the cold air outside and you. This allows for a warm microclimate formation with your body heat.

              • Fill material itself also takes a role in the bag’s warmth, but small.

              • A synthetic sleeping bag, in fact, can distribute the same coziness as a down one, just be heavier. So, this element will be for other additional requirements of yours when choosing a sleeping bag, such as comfort, lightness, maintenance process, and budget.

              • To determine a bag’s warmth, the real feature that you should consider is its temperature rating. Three common ranges are:

              +15°F and lower: For winter

              +15°F to +30°F: A great all-rounder, perfect as a 3-season bag

              +30°F and higher: For summer

              • Pro-tips:

              • Pick a bag that’s 5°F to 10°F lower than the lowest ambient temperature you expect to sleep in. For example, if it’s maximum down to +5°F overnights, pick a sleeping bag featuring -5°F of temperature rating.

              Bag Shape

              • Different bag shape or the bag cut creates different extra spaces inside it.

              • How this feature affects a bag’s warmth?

              • The more the excess space inside a bag, the less thermal efficient it will be.

              • However, some extra space is necessary since it can accommodate a few more layers of clothes you want to wear or essentials you want to keep warm together during night sleep.

              • So, a bag with a snug fit and a sleek shape is the best choice for warmth. There are three basic bag shapes: Rectangular, Mummy, and Semi-rectangular.

              • But mummy is considered the warmest out of a bunch because it optimizes those requirements mentioned above.

              • To have more freedom when moving inside a bag, the semi-rectangular is worth considering but understand that looser fit will lead to less thermally efficient.

              Additional Features

              To get more warmth in colder temperature nights, you can also consider these additional features:

              • Draft Tube: It runs along the bag length, behind the zippers to lock warm air inside.

              • Yokes/draft collars: Work like the draft tube but in this case, they are around the neck area.

              • Hood: It offers extra warmth to your head and face. Usually, come with a drawstring to cinch down and avoid cold air outside in.

              Which Brands Make The Warmest Sleeping Bags?

              Hyke & Byke

              • Rare sleeping bag brands that provide a wide range of lengths to ensure the best fit for different body shapes and sizes. The down fill is guaranteed to take from high-quality, reliable sourced suppliers for decent warmth and safety.

              Outdoor Vitals

              • Outdoor Vitals sleeping bags allow users to relocate down to the easy-to-freeze body parts, like feet, without increasing their total weight. Their products also retain the lightest weight in this industry for effortless portability.

              Klymit

              • Klymit products are well-loved by female sleepers due to their extended chest and hip areas while narrowing down the shoulder space. They are also a well-known brand for high-quality down sleeping bags with thermal efficiency.

              TETON

              • TETON with their diverse lines, affordability, and durability will surely fit your sleeping demands and budget. Their synthetic insulation highlights breathability and weight-to-warmth ratio to provide toasty coziness to users.

              Suisse

              • Suisse sleeping bag lines emphasize the exclusive synthetic fill for maximum warmth while keeping the decent lightness and compact pack size for portability. The fill even distribution also avoids the discomfort of cold spots effectively.

              FAQs

              How long does sleeping bag last?

              Depend on how you maintain the bag as well as how often and how hard you use it, a down model can last 4-10 years while a synthetic is 2-5 years.

              Do sleeping bag liners keep you warmer?

              If the sleeping bag liners are cotton/fleece/silk, it will boost the warmth of your sleeping bag.

              How do you add warmth to a sleeping bag?

              Some helpful ways to add warmth to a sleeping bag are:

              • Wear extra layers of thermal clothes

              • Add thermal liner

              • Wash your old sleeping bag

              Do sleeping bags lose their warmth?

              Yes, they do. How soon of a sleeping bag losing its warmth will be based on:

              • Proper storage

              • How hard you are on it

              • How often it’s used

              Is it warmer to sleep with clothes on or off in a sleeping bag?

              If you put on thermal clothes, like thermal underwear, beanie, socks, it will be warmer.

              Pro-tips: Remember to wear them an hour or more before going to bed to get the most comfort and warmth.

              How do you take care of a sleeping bag?

              A full, proper maintenance process will have 3 parts:

              • Proper use
              • Washing
              • Storage

              For more detail, this article is a good reference.

              Conclusion

              With an ultimate buying guide and some FAQs included, I hope this article has unraveled as many mysteries around choosing the warmest sleeping bags as possible.

              Once figuring out your specific needs and budget, I believe it’s much easier to make a choice within 6 options I’ve given to you above. Thanks for reading!


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