If there is one thing you can never leave out of your camping checklist, it’s a reliable sleeping bag that will keep you warm and dry while you spend the night under the stars. The best summer sleeping bags are highly compressible, packing down to a size that doesn’t take up too much space in your pack. They are insulated to protect you against moisture and humidity, and they add minimal weight on your shoulders when backpacking. In order to help you choose among hundreds of different models, we have selected the five best summer sleeping bags available on the market, accounting for price, warmth and, of course, comfort.
For a complete analysis of all backpacking sleeping bags, check out the buyer’s guide Best Backpacking Sleeping Bags.
Quick Answer - The Best Summer Sleeping Bags
- Marmot Nanowave 45
- Nemo Forte 35
- Kelty Cosmic 40
- Therm-a-Rest Space Cowboy 45
- Marmot Hydrogen 30
Comparison Table - Best Sleeping Bags for Summer
For the best experience turn your device horizontally| Name | Insulation | Temp Rating | Weight | Shape | Price | Rating | Review |
|---|---|---|---|---|---|---|---|
| Marmot Nanowave 45 | Synthetic | 56 F | 1.8 lbs | Mummy | $79 | 4.2 | Read Review |
| Nemo Forte 35 | Synthetic | 40 F | 2.1 lbs | Semi-rectangular | $160 | 4.7 | Read Review |
| Kelty Cosmic 40 | Down | 48 F | 1.7 lbs | Mummy | $110 | 4.5 | Read Review |
| Therm-a-Rest Space Cowboy 45 | Synthetic | 52 F | 1.2 lbs | Mummy | $140 | 4.5 | Read Review |
| Marmot Hydrogen 30 | Down | 33 F | 1.4 lbs | Mummy | $399 | 4.4 | Read Review |
| Name | Insulation | Temp Rating | Weight | Shape | Price | Rating | Review |
Temp ratings refer to the EN or ISO Comfort rating.
Weight and price are shown for the regular size.
Reviews - Best Summer Sleeping Bags
Marmot Nanowave 45
Specs
- Insulation: Synthetic
- Weight: 1.8 lbs
- Shape: Mummy
- Temp Rating: 56 F
Features
- Draft tube keeps cold air from seeping through zipper
- Zipper wraps around foot box
- Synthetic insulation traps warmth even when wet
The Marmot Nanowave 45 is an affordable summer sleeping bag that won’t take up too much room in your backpack. Not only is it cheap, it’s also practical and functional.
In awarding it the winner of the best under $100 category, we realize it’s not quite fair because most other bags on this list have a temperature rating down to around 20 degrees. However, if you’re on a super tight budget and plan to camp from mid-spring to mid-fall, the Nanowave 45 is hard to beat.
Which leads us to the biggest downside of this bag, it is only good in mild weather. But, not everyone needs or wants a super warm bag and if you combine the Nanowave with an extra warm sleeping pad and a thermal liner, you might be able to extend the temperature range of this bag down a few degrees, making it much more versatile. If you’re looking for a warmer budget backpacking sleeping bag, check out the REI Trailbreak 20.
The Marmot Nanowave is also available in a 55-degree and 35-degree version.
Nemo Forte 35
Specs
- Insulation: Synthetic
- Weight: 2.1 lbs
- Shape: Semi-rectangular
- Temp Rating: 40 F
Features
- 80% postconsumer recycled content.
- Unique Spoon™ shaped bags offer more room at the elbows and knees, allowing side sleepers to shift positions comfortably throughout the night.
- Waterproof/breathable foot-box withstands tent condensation, keeping feet warm and dry.
The Nemo Forte 35 is an affordable synthetic sleeping bag that has plenty of room for those who love to sprawl out. This bag is a great option for mild weather adventures where you don’t have to travel too far to get to your campsite.
What we love the most about this bag is its spacious dimensions. If you’ve ever felt trapped in a narrow mummy bag, you’ll love the Forte’s hourglass shape that is wider at the shoulders and feet and slightly tapered at the hips. This design is perfect for side sleepers or people who tend to move around a lot at night. We also loved what NEMO calls thermo gills, they are zips that let the insulation spread apart which is great for warm summer nights.
The biggest drawback of this bag is its weight and pack size. At 2lbs 2 oz, it’s not the best choice for long distance backpacking but is manageable for overnight trips. The Forte uses Primaloft synthetic insulation which has its pros and cons. It doesn’t pack down as small as down but it is far more affordable.
If you love the idea of this bag but wish it had down insulation, check out the Nemo Disco line.
This sleeping bag also comes in a 20 degree version.
The Nemo Forte also comes in a women’s specific version in both 20 degree and 35 degree versions.
Kelty Cosmic 40
Specs
- Insulation: Down
- Weight: 1.7 lbs
- Shape: Mummy
- Temp Rating: 48 F
Features
- Dual-slider locking zippers.
- Zipper draft tube with antisnag design makes it easy to get in and out of the bag.
- Stuff sack included.
The Kelty Cosmic 40 is an affordable summer down sleeping bag that is an excellent option for new backpackers who don’t mind carrying a bit of extra weight and bulk to save some cash.
What we love the most about this bag is its overall value. The Cosmic’s quality and warmth outshine other budget sleeping bags on this list. Of course, you can’t compare the build and material quality of the Cosmic to the top of the line bags on this list but it is practical and comfortable enough, making it tough competition for other budget options.
The biggest downside of the Cosmic is it is much more heavy and bulky than other backpacking sleeping bags, but it might be a worthy trade off if saving cash is your biggest priority. The added pounds and pack size come from its 550 fill-power-down which isn’t as performance minded as 800 and 900 fill-down found in high ticket bags. If you’re just starting out and the idea of spending the majority of your budget on a sleeping bag is making you nervous, the Kelty Cosmic 40 might be a great choice to get you outside fast.
This bag is also offered in 20-degree and 0-degree versions.
Therm-a-Rest Space Cowboy 45
Specs
- Fill Weight: 04.2 oz
- Insulation: Synthetic
- Weight: 1.2 lbs
- Shape: Mummy
- Volume: 02.0 L
- Temp Rating: 52 F
- Fill Power: Polyester
Features
- Water Resistant
- Highly Compressible
- Cinchable Hood And Snag Free Zipper
BEST LIGHTWEIGHT & BUDGET-FRIENDLY SLEEPING BAG
The Therm-A-Rest Space Cowboy 45 is an awesome ultralight mummy-shaped sleeping bag. Its compressed volume of 2 liters makes it highly packable and lightweight. Because this sleeping bag only withstands 45°F, it is better suited for warmer weather and summer camping. However, you can layer it with other quilts using blanket loops on the bag, expanding its versatility. Additional removable connectors even let you fasten a sleeping pad to the bag.
The Cowboy 45 uses water-resistant synthetic fill that retains its insulation abilities even when damp. It is strategically placed in certain areas to optimize warmth and weight. The ThermaCapture lining efficiently traps body heat. Additionally, a cinchable hood also guards against unwanted drafts. All these features make the Space Cowboy 45 a great companion for backcountry travels.
Marmot Hydrogen 30
Specs
- Fill Weight: 10.9 oz
- Insulation: Down
- Weight: 1.4 lbs
- Shape: Mummy
- Volume: 06.8 L
- Temp Rating: 33 F
- Fill Power: 800
Features
- Strong And Durable
- Broad, Long, And Roomy
- Extra Zipper On The Side
The insulating features of the Marmot Hydrogen Down Sleeping Bag will surely keep you warm even through colder nights. An insulated tube covers the 2-way anti-snag zipper to prevent any cold breeze from seeping in. A fold-down second zipper equips you with ventilation, so you won’t overheat on warmer nights. Moreover, an insulated hood will warmly cradle your head thanks to its multi-baffle design that keeps the down from moving by separating it into different compartments. And cinching drawcords at the top of this bag allow you to secure the hood around your face to prevent wind from chafing your face all night.
Unlike a caterpillar cocoon, this mummy sleeping bag is durable and sure to live a long life. It has two hang loops for storing, drying, or just airing out the bag to help increase its lifespan with proper care. Another nifty feature includes an internal stash pocket perfect for keeping nighttime essentials and valuables nearby. Considering all these specs, the bag’s super light weight of 1 lb. 7 oz. is almost unbelievable.
THINGS TO CONSIDER WHEN BUYING THE BEST SUMMER SLEEPING BAGS
Summer is for many the ideal season to go and explore the great outdoors, with comfortable temperatures even at higher altitudes and a lower risk of rainfall. But when it comes to camping, it is fundamental to choose the best sleeping bag to suit your needs. To get the proper amount of rest on the trail after a day spent walking in the backcountry, you’ll need to choose the right sleeping bag for you while considering shape, size, weight, and temperature rating.
SLEEPING BAG SHAPE
Sleeping bags come in three different shapes: rectangular, semi-rectangular, and mummy-shaped.
Rectangular-shaped sleeping bags offer maximum moving space but minimum insulation, as cold air pockets are more likely to form in the empty areas. They are also bulkier, therefore less suitable for backpacking trips.
Semi-rectangular sleeping bags have a tapered shape that gets narrower around the legs and feet. They are usually still wide enough to allow for some movement, but tend to be lighter in weight, given they use less material in their production.
Mummy-shaped sleeping bags provide the most insulation with the minimum weight, but offer little or no moving space. Their shape is anatomical, meaning that they tend to wrap tighter around the body to reduce heat loss and bulk.
TEMPERATURE RATING
Most sleeping bags are tested by independent organizations in a laboratory to establish at what temperature they cease to be comfortable to sleep in. The number that accompanies the sleeping bag’s name refers to the lowest temperature at which the average “cold sleeper” wearing one layer of clothing will be comfortable.
Summer sleeping bags have a temperature rating of 32°F and above, while three-season sleeping bags start at 20°F. If you are planning to hike at high elevation where temperatures drop close to freezing level even in summer, you will want to buy a 3-season sleeping bag with a temperature rating of 30°F or lower. If you intend to camp in a warm climate a sleeping bag with a rating of 40°F + will do perfectly fine.
INSULATION
The insulating material that fills sleeping bags is usually either down or synthetic fiber. Down-filled sleeping bags tend to be more expensive than those with synthetic insulation, they perform better in colder temperatures, and they weigh less.
On the other hand, sleeping bags with synthetic insulation dry faster, are non-allergenic, and protect against heat loss even when damp. In summer months, when much insulation isn’t needed, synthetic sleeping bags are usually more than enough to keep you warm.
WEIGHT
As for most camping and hiking gear, weight can have a huge impact on the cost of the product. Ultralight sleeping bags often come at a premium price but are worth the investment if you are planning a multi-day backpacking trip, as they are highly compressible and won’t put too much pressure on your shoulders. Summer sleeping bags are lighter than 3-season or winter bags, as less insulation material is required for the fill.
COST
Summer sleeping bags are less costly than winter or 3-season bags. However, prices vary widely as different materials and technologies are employed in their production. Prices for summer sleeping bags start at around $50. They go up into the hundreds depending on several factors. These are the quality of the insulating material, weight, brand name, and additional features such as extra pockets, double zippers, and waterproof coating.
FEATURES EXPLAINED
Temperature rating
The lowest temperature at which an average “cold sleeper” wearing one layer of clothing is comfortable. Summer sleeping bags start at 32°F.
Synthetic insulation
Synthetic insulation material consists of polyester fibers that fill the sleeping bag to prevent heat loss. The synthetic insulation materials vary in quality, with the best being comparable to duck or goose down in terms of heat-retention.
Duck or goose down
The soft, fine plumage that is found under the feathers of ducks and geese, working as an insulating layer on top of the skin. This type of plumage is often used to fill down sleeping bags for superior warmth and insulation.
Fill power
Most duck or goose down summer sleeping bags have a fill power (fp) that ranges between 600 and 700. This rating indicates the number of cubic inches one ounce of down occupies when compressed under a standard weight. In other words, this rating refers to the quantity of insulating material in the sleeping bag, not the quality. Mediocre fill power starts around 500, whereas high-end sleeping bags can have a fill power up to 900.
Sleeping bag shell
The outer material of the sleeping bag, usually made of polyester or nylon coated with a DWR (durable water repellent) finish.
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For more of our top hiking & backpacking gear recommendations, check out these popular buyer's guides:
Best Backpacking Sleeping Bags
Best Backpacking Sleeping Pads