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The Kelty Mistral 40 sleeping bag emerges as a beacon in the realm of outdoor sleeping solutions, designed with a philosophy that revolves around delivering everything you need and nothing you don’t. Crafted to put evening chills in their place – elsewhere, this sleeping bag is a testament to Kelty’s commitment to providing outdoor enthusiasts with a warm and cozy refuge in the great outdoors.

Mistral 40 Sleeping Bag
Temp Rating: 40° / 4°C
Fits to: 6’ / 183 cm
Length: 76” / 193 cm
Fill weight: 29 oz. / .83 kg
Total weight: 2 lb. 12 oz. / 1.3 kg
Stuffed size: 9″ x 16″ / 23 x 41 cm

See the Kelty Mistral 40 Sleeping Bag

Key Features

These key features collectively make the Kelty Mistral 40 a standout choice for outdoor enthusiasts seeking a reliable and comfortable sleeping companion that effortlessly combines essential features for a restful night under the stars.

Cozy Cloudloft™ Synthetic Insulation:

Crafted to provide optimal warmth and padding, the Cozy Cloudloft™ synthetic insulation ensures a comfortable night’s sleep, making it an ideal choice for chilly outdoor environments.

Polyester Taffeta Shell and Liner:

The Kelty Mistral 40 boasts a durable Polyester 190T taffeta shell and liner, striking the perfect balance between rugged outdoor use and comforting coziness, ensuring longevity and comfort in varying conditions.

Offset Quilt Construction:

The innovative offset quilt construction goes beyond the ordinary, effectively preventing pesky cold spots. This thoughtful design ensures an even distribution of warmth, enhancing the sleeping experience in unpredictable outdoor temperatures.

Natural-fit Spacious Footbox:

Offering more than just a place for your feet, the natural-fit spacious foot box provides ample room for toe-wiggling freedom, adding an extra layer of comfort to your outdoor sleeping arrangements.

Comfort Hood:

The inclusion of a comfort hood is a testament to the meticulous design of the Kelty Mistral 40. This feature not only keeps the cold at bay but also helps trap heat inside, creating a snug cocoon for a restful night’s sleep.

Anti-snag Zipper Design:

Frustration-free operation is guaranteed with the anti-snag zipper design. This thoughtful addition ensures smooth zipping and unzipping, eliminating any potential nuisances during use.

Draft Tube:

The strategically placed draft tube backing the zipper acts as a guardian against heat loss and chilly drafts, reinforcing the bag’s ability to retain body warmth and keep cold air out.

Functional Design Elements

The Mistral 40 stands out not only for its comfort-oriented features but also for the functional design elements that enhance its overall usability. An integral part of this design is the Anti-Snag Zipper, ensuring a seamless experience when entering or exiting the sleeping bag. This thoughtful addition prevents frustrating snags, making it effortless to adjust ventilation or exit the bag without any hassles. The user-friendly design extends to the Draft Tube backing the zipper, a strategic feature that acts as a thermal barrier, effectively keeping body heat inside and external cold air out. This not only optimizes insulation but also ensures a consistent and cozy sleeping environment throughout the night.

Another noteworthy design element is the Offset Quilt Construction, a feature specifically engineered to eliminate cold spots. The quilted pattern ensures an even distribution of insulation, preventing temperature irregularities that could disrupt your sleep. This meticulous design choice caters to the demands of outdoor enthusiasts who value a dependable sleeping bag that can perform consistently in a variety of conditions. As we delve deeper into the functional design elements, it becomes clear that the Mistral 40 isn’t just about providing warmth; it’s about creating an optimized and reliable sleeping experience for outdoor adventurers.


These specifications collectively showcase the meticulous design and versatile features of the Kelty Mistral 40 sleeping bag, making it a standout choice for outdoor enthusiasts seeking a reliable and adaptable sleeping solution.

  • Temperature Ratings: The Kelty Mistral 40 sleeping bag is tailored for comfort in cooler climates, with a temperature rating of 40 degrees Fahrenheit (4 degrees Celsius), making it an excellent choice for mild to moderate cold weather conditions.
  • Weight: Available in two sizes, the Regular – Right Zip variant weighs a mere 2 lbs. 14 oz., while the Long – Right Zip slightly increases the weight to 3 lbs. 1 oz. This lightweight construction ensures easy portability during outdoor expeditions.
  • Shell Material: Built for durability, the shell features Polyester 190T taffeta, striking a balance between toughness and comfort. This material choice ensures longevity, making the sleeping bag resilient against the rigors of outdoor use.
  • Insulation Type: The Mistral 40 employs Cloudloft synthetic fibers as its insulation, providing an efficient balance of warmth and comfort. This synthetic insulation is also known for its resilience in damp conditions, enhancing the sleeping bag’s versatility.
  • Fill Weight: The Regular – Right Zip variant contains 1 lb. 12.8 oz. of Cloudloft synthetic insulation, while the Long – Right Zip version features a slightly higher fill weight at 1 lb. 14.4 oz. These variations cater to different preferences and body sizes.
  • Lining Material: The interior of the sleeping bag features Polyester 190T taffeta lining, ensuring a soft and comfortable feel against the skin. This lining contributes to the overall coziness of the sleeping experience.
  • Sleeping Bag Shape: Designed in a Mummy shape, the Kelty Mistral 40 optimizes heat retention by conforming closely to the body. This shape is particularly efficient in preventing drafts and maintaining warmth in various sleeping positions.
  • Size Measurements: The Regular – Right Zip variant accommodates individuals up to 72 inches in height, with a shoulder girth of 62 inches and a hip girth of 58 inches. The Long – Right Zip version provides extra length, accommodating individuals up to 78 inches, with a shoulder girth of 64 inches and a hip girth of 60 inches.
  • Stuff Sack: The sleeping bag conveniently compresses into a compact 9 x 16 inches stuff sack, with a volume of 16.68 liters. This makes it easy to pack and carry, ensuring it doesn’t take up much space in your outdoor gear collection.

Portability and Ease of Use

The Mistral 40 sleeping bag excels not only in providing a cozy night’s sleep but also in its remarkable portability and user-friendly design. Weighing in at just 2 lbs. 14 oz. for the Regular – Right Zip variant and 3 lbs. 1 oz. for the Long – Right Zip, this sleeping bag is a lightweight companion for backpackers and outdoor enthusiasts on the move. Its compact design and inclusion of a 9 x 16 inches stuff sack, with a volume of 16.68 liters, make it exceptionally easy to stow away in your backpack, leaving ample space for other essential gear.

The user-friendly features contribute to the overall ease of use, ensuring that setting up camp and settling down for the night is a hassle-free experience. The Anti-Snag Zipper Design guarantees smooth and frustration-free zipping, allowing for quick adjustments without the risk of snags. Additionally, the Draft Tube backing the zipper not only enhances insulation but also aids in easy zipper operation. These design elements make entering and exiting the sleeping bag effortless, even in low-light or chilly conditions.

Whether you’re a seasoned backpacker trekking through varied terrains or a casual camper seeking simplicity, the Kelty Mistral 40’s portability and ease of use make it a reliable choice for those who prioritize convenience without compromising on comfort during their outdoor adventures.

What I like about this bag

  • Cozy Cloudloft™ Synthetic Insulation: Offers optimal warmth and padding for a comfortable night’s sleep.
  • Durable Shell and Liner: Polyester 190T taffeta construction ensures durability and comfort, standing up to the rigors of outdoor use.
  • Offset Quilt Construction: Prevents cold spots, ensuring an even distribution of warmth throughout the sleeping bag.
  • Spacious Footbox: Natural-fit design provides extra room for toe movement, enhancing overall comfort.
  • Comfort Hood: Effectively keeps the cold out and retains heat, contributing to a snug sleeping environment.
  • Anti-Snag Zipper Design: Ensures smooth and frustration-free zipping, enhancing overall ease of use.
  • Draft Tube: Backing the zipper, it acts as a thermal barrier, preventing heat loss and keeping cold air out.
  • Mummy Shape: Optimizes heat retention, especially beneficial in cooler conditions.
  • Portability: The lightweight design and compact stuff sack make it easy to carry during outdoor adventures.

What I don’t like about this bag

  • Temperature Range: While suitable for mild to moderate cold weather, the Mistral 40 may not be ideal for extremely low temperatures.
  • Synthetic Insulation: While effective, synthetic insulation may not compress as much as down, potentially affecting the packed size.
  • Specific Zipper Location: The sleeping bag is available with a right zipper only, which may be a consideration for those with specific preferences.
  • Limited Sizing Options: While available in Regular and Long sizes, some users may desire more size options for a tailored fit.
  • Not Suitable for Cold Weather: The 40-degree rating makes it less suitable for cold-weather camping.

Final Verdict

The Kelty Mistral 40 sleeping bag stands as a testament to thoughtful design and practical functionality, offering outdoor enthusiasts a reliable and comfortable refuge for their nights under the stars. With a focus on delivering essentials, this sleeping bag excels in key features such as the Cozy Cloudloft™ Synthetic Insulation, Polyester Taffeta Shell and Liner, and the Offset Quilt Construction, ensuring a warm and even sleep experience.

Its user-friendly design, highlighted by the Anti-Snag Zipper and Draft Tube, enhances overall ease of use, allowing for seamless entry and exit. The Mummy shape, combined with a spacious foot box and a comfort hood, optimizes heat retention, ensuring a snug and restful night’s sleep in various conditions.

Moreover, the Mistral 40 doesn’t compromise on portability. Weighing in at just under 3 pounds, it’s a lightweight companion that compresses neatly into a compact stuff sack, making it an ideal choice for backpackers and campers on the go.