4 best 40 degree sleeping bags

A 40-degree sleeping bag is a type of sleeping bag specifically designed for outdoor enthusiasts and campers who plan to camp in moderate to warm weather conditions. Here's what you need to know about 40-degree sleeping bags:

Temperature Rating:
- The "40-degree" in the name refers to the temperature rating of the sleeping bag. This rating indicates the lowest temperature at which the bag is suitable for use without the need for additional insulation or layers.
- A 40-degree sleeping bag is intended for mild to warm weather camping, typically during late spring, summer, and early fall when temperatures are not expected to drop significantly below 40 degrees Fahrenheit (4 degrees Celsius).
Design and Insulation:
- These sleeping bags are often designed to be lightweight and compact for easy portability.
- They may be filled with synthetic insulation or down insulation, with each offering its own set of advantages. Synthetic insulation tends to perform better when exposed to moisture, while down insulation is known for its superior warmth-to-weight ratio.
Features:
- Many 40-degree sleeping bags come with features such as a full-length zipper for ventilation, a hood with a drawstring to keep your head warm, and an internal stash pocket for small essentials like a phone or flashlight.
- Some models may have a draft tube along the zipper to prevent cold air from entering and warm air from escaping.
Size and Shape:
- These bags are typically designed in a mummy shape to minimize dead space inside the bag, which helps retain body heat more effectively.
- Some 40-degree sleeping bags are available in different lengths to accommodate different body sizes.
Versatility:
- 40-degree sleeping bags are ideal for warm-weather camping, but they can also serve as a useful addition to your gear for layering in colder conditions.
- For colder weather, you can pair a 40-degree bag with a liner or additional clothing layers to increase warmth.
Weight and Packability:
- Since they are intended for lightweight and warm-weather use, 40-degree sleeping bags are often among the lightest and most compact options available.
- This makes them suitable for backpacking and other activities where minimizing weight and bulk is important.
Care and Maintenance:
- To prolong the life of your sleeping bag, it's essential to follow the manufacturer's care instructions, which may include proper storage, cleaning, and maintenance guidelines.

Remember that the comfort level of a sleeping bag can vary depending on factors such as your metabolism, clothing, and the insulation of the sleeping pad used underneath.Always check the weather conditions of your camping destination and choose a sleeping bag with an appropriate temperature rating to ensure a comfortable and safe night's sleep while outdoors.

Below you can find our editor's choice of the best 40 degree sleeping bags on the market

Kelty Cosmic 40 Degree Down Sleeping Bag

Kelty

Based on 33 reviews Check latest price

Product description

The Kelty cosmic 40 degree Dri down Regular sleeping bag features cozy, quick-drying 600 fill Dri down insulation and soft-as-silk nylon taffeta fabric lining which means you're to be comfy and sleep well. Stuff sack included.

The Kelty Cosmic 40 Degree sleeping bag is ideal for 2-season backpacking and camping. Water-resistant down insulation and an array of features make this sleeping bag a great combination of value and comfort.
This sleeping bag is insulated with 600-fill DriDown. Renowned for efficiency in retaining heat and compressible properties, down has an incredibly soft, comfortable feel, and continues to provide the best warmth-to-weight ratio of any insulation.
Employing a unique, innovative polymer application, DriDown actually creates a hydrophobic finish on each individual plume of down. This treatment results in insulation that stays dry longer and dries faster.
A draft tube behind the 60" two-way locking anti-snag zipper and an insulated hood enhance the thermal efficiency of the Cosmic 40 Degree bag.
A polyester taffeta liner provides internal comfort. Other features include a small pocket to keep electronics handy and a naturally-shaped foot box.
Ultra-Compressible: packs down to a 7x6x6 inch stuff sack for easy, lightweight carry and storage.

User questions & answers

Question:	How much is it weigh
Answer:	Sensor must be placed outside to observe outdoor conditions. Sensor is water resistant and is designed for general outdoor use, however, to extend its life place the sensor in an area protected from direct weather elements. Hang the sensor using the integrated hang hole or hanger, or by using string (not included) to hang it from a suitable location, like a well covered tree branch. The best location is 4 to 8 feet above the ground with permanent shade and plenty of fresh air to circulate around the sensor.
Question:	How much weight is it
Answer:	Hi there!!! Thanks for beeing an Amazon customer!! Probably someone bought the moment you clicked and the price went up because the cheapest seller's stock ran out.
Question:	I’ve never used a mummy type sleeping bag, how does it do for overweight people? I wear a 2X
Answer:	It does not light up.
Question:	How long is a regular vs. long
Answer:	yes Will work in the desert
Question:	is the transmitter waterproof
Answer:	The transmit and receiver units will send and receive signals from exterior to interior locations up to a reasonable distance (in my current location that's about 30 feet). It seems reasonable that the signal would transmit to the unit in a garage 25 feet away although I have no means to test such a set up.
Question:	I clicked on the add that said $12.99 and its
Answer:	Yes
Question:	does it light up
Answer:	Yes. We picked up a second one, and at some point, both receivers end up reading the same outdoor sensor. It's still ok for having 2 indoors in different rooms, but the outdoor reading ends up merging, or randomly reading different sensors. So we just use one outdoor sensor and leave the other without batteries.
Question:	What is the max exterior temperature measured? Will it work in the desert where it can get 130 degrees f plus
Answer:	It resets automatically after batteries from both units have been removed (at the same time) then replaced with new ones (I put fresh ones in the main unit first, then the remote).

Product features

PFC-Free water resistance

Simply put, Dridown represents the evolution of down insulation. Regular down is treated with a molecular level polymer to create a hydrophobic finish on each individual down plume. This finish allows DriDown to stay dry longer, without harmful PFCs. Easy on the eyes, easy on the environment.

Increased insulation over untreated down

Kelty's Dridown treated down technology retains more loft than untreated down when exposed to moisture and humidity. Bring it on mother nature.

Nylon shell and treated down create a barrier between you and the elements.

20D Nylon Taffeta shell repels and prevents moisture buildup, and Dridown insulation resists wet conditions from reaching soaking through the bag. The combination presents a clear advantage over traditional down, while retaining traditional properties.

Get back to comfort quickly

Rain happens. Dridown will resist bunching, soaking, and water retention within the bag, ensuring it can dry out quickly and efficiently. We aren't fair weather campers, after all.

Ridge 40 Degree Hibernate Sleeping Bag

Ledge Sports

Check latest price

Product description

Zipper: #5 - Two Way Dimensions: 30" W x 75" L Temperature Rating: 40 Degrees Fahrenheit/6 Degrees Celsius Fill: Hibernate Micro Denier Synthetic Weight: 2.7 pounds Shape: Rectangular with hood Ultra Lightweight and Easy to Pack - these sleeping bags pack down into an ultra compact bag in seconds. There’s no need to fold or roll it. Just stuff it into the sturdy carrying bag, pull the straps, and it folds down into a small, light two pound package that will easily fit in any backpack. Roomy and Comfortable - at 30 x 75 inches, these sleeping bags are incredibly roomy for any adult or child under 6’1. It’s easy to get in, get out and turn around to find a comfortable sleeping position. The zipper stays closed, and the plush filling means you’ll sleep like a baby. Colors and Designs For The Whole Family - with 4 bright, vibrant colors and designs to choose from, every member of your family will find a sleeping bag they love. And mom and dad can even zip up two bags to create one large super snuggly double sleeping bag.

Kelty Sleeping-Bags Kelty Mistral Synthetic Camping Sleeping Bag

Kelty

Based on 77 reviews Check latest price

Product description

What good is overpriced gear when you don’t have the money left over for park fees and gas to get there? Designed to give you everything you need and nothing you don’t, the Mistral delivers backcountry necessities like a comfort hood and spacious footbox, and with draft-locked zippers to put evening chills in their place: elsewhere.

Budget Friendly: Conquer sleep in the outdoors, without killing your budget. The Mistral is designed to give you everything you need, and nothing you don’t.
Durable Materials: Outer shell and inner liner both made using durable and soft 190T Teffeta Polyester. Equal parts comfortable and weather-ready, the bag is made to last season after season, and made for play.
Offset Quilt Pattern: The Quilt-style stitch pattern provides the most efficient, even coverage of insulation throughout the bag, eliminating cold spots (or hot spots).
Synthetic Insulation: Kelty’s Cloudloft insulation (the same fill we use in our camp pillows and doublewide sleeping bags) provides reliable warmth, cushion, and comfort for your night under the stars.
Kelty Craftsmanship: Kelty is synonymous with quality in the outdoor community. Kelty gear is built for play, and built to last. The Mistral sleeping bag is ready to be put through the ringer on the trail, campground, and everywhere in between.
20 Degree Temp Rating, Long Size: Fits sleepers up to 6ft 6in, fill weight 36oz, total weight 3lbs 5oz, stuff size (non-compressed) 17x10 inches. Color: Tapestry

User questions & answers

Question:	How small can you compress it
Answer:	You will probably not like it. A mummy bag is designed to be efficient in that you are not heating up extra space in the bag. Try something like the Kelty Galactic 30 down bag which is a semi rectangular design.
Question:	Is the 0 degree rating the extreme temperature rating or the comfort temperature rating
Answer:	The regular fits to 6' and the long fits to 6' 6"

Kelty Light Year XP 40-Degree Sleeping Bag

Kelty

Based on 8 reviews Check latest price

Product description

The Light Year XP 40 degree is a summer-weight synthetic bag with a hip-length zipper and zippered foot vent that is perfect for lgith and fast adventrues in unpredicatable conditions.

40 F/4 C Mummy
Insulation: Climashield XP. Shell: NPR241T nylon-polyester diamond cross-dye ripstop. Liner: P300T polyester microfiber pongee
Quilt-through construction and chevron stiching.
Efficient, form fitting hood.
Zipper darft tube with anti-snag design and zipper foot vent

User questions & answers

Question:	what is the stuff sack size
Answer:	No 0 Degree is the estimated comfort rating. Extreme would be below 0. Be advised for any sleeping bag to work at it's adverstied comfort rating, it will need to be stored outside it's stuff sac. When using the bag you will use the stuff sack. When you take the sleeping bag out of the stuff sack you will need to spend a little time re-lofting the bag like you would with a pillow. It is the loft of a sleeping bag that provides the warmth.
Question:	Are you sure that the insulation is CLIMASHIELD? Other sites say ECOPET SOFT
Answer:	The Cosmic Down 40 weighs 1lb 10oz for a regular and 1lb 13oz for a long.
Question:	What is the weight of this bag
Answer:	1lb 9.7oz, Long 1lb 12oz