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Western Mountaineering Summerlite Review

A stellar choice for those looking for a warm, lightweight, fully hooded mummy.
Editors' Choice Award
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Price:  $410 List | $410.00 at Backcountry
Compare prices at 2 resellers
Pros:  Warmth-to-weight ratio, excellent fabric, Made in the USA
Cons:  Tight fit, shallow hood, expensive
Manufacturer:   Western Mountaineering
By Ethan Newman ⋅ Review Editor  ⋅  May 13, 2019
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70
OVERALL
SCORE


RANKED
#3 of 13
  • Warmth - 30% 8
  • Weight - 25% 6
  • Comfort - 20% 6
  • Versatility - 15% 8
  • Features - 10% 7

Our Verdict

There's a lot to like about the Western Mountaineering Summerlite. It's lightweight, especially for a fully hooded mummy. The materials are of high quality, and most of the features are well thought out, as we've come to expect from this manufacturer. It's quite toasty, one of the warmer bags for its rating, but can be vented effectively with the full-length zipper. However, in order to achieve the warmth to weight ratio, it sacrifices some space. Still, we think it's an excellent bag, enough to win our Editors' Choice Award for an ultralight hooded bag. If you're looking for a traditional hooded mummy bag, and don't mind slightly tighter cut, this is an excellent option that combines a very low weight with warmth, a full-length zip, and very high quality overall.

If you prefer to forgo a hood, the time-tested and heavily vetted Feathered Friends Flicker remains the best hoodless UL bag we have ever reviewed. Going for the FF Flicker will also save you some cash, but if you prefer a hood, you'll be hard-pressed to do better than the Summerlite.


Compare to Similar Products

 
Awards Editors' Choice Award Editors' Choice Award Best Buy Award  Top Pick Award 
Price $410.00 at Backcountry
Compare at 2 sellers
$364.00 at Feathered Friends$300 List$379 List$398.95 at Backcountry
Compare at 2 sellers
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Pros Warmth-to-weight ratio, excellent fabric, Made in the USAHighest scoring ultralight sleeping bag, best features, and most versatileVery affordable, highly customizable, versatile, lots of featuresWarm for an ultralight bag, simple and versatile design, box baffle construction, waterproof stuff sackWarmer than the fully hooded mummies lighter than it, comfortable liner material, roomy footbox, ¾ length zipper
Cons Tight fit, shallow hood, expensive40 degree not as warm as others, neck draw cords loosen over timeLong wait for product to be custom made and shipped, foot box draw cord still leaves a little hole, lots of buttons and strapsA little constricting, small foot box, not the best neck draw cord designMore suitable for 40F temps than 30, no neck baffle, zipper catches on fabric easily
Bottom Line A stellar choice for those looking for a warm, lightweight, fully hooded mummy.The highest scorer because of its versatile design that allows it to be a fully opened blanket or a fully zipped hoodless mummy.Offers the versatility of sleeping under it as a blanket or fully wrapped up, with a huge range of customizable options.A top-scoring bag that's warm and versatile enough for full three-season use, while weighing impressively little.A high-quality hooded mummy bag that is significantly lighter than a standard backpacking bag.
Rating Categories Summerlite Flicker 40 UL Revelation 20 ZPacks Classic Marmot Phase 30
Warmth (30%)
10
0
8
10
0
6
10
0
8
10
0
8
10
0
6
Weight (25%)
10
0
6
10
0
6
10
0
6
10
0
6
10
0
7
Comfort (20%)
10
0
6
10
0
7
10
0
6
10
0
6
10
0
7
Versatility (15%)
10
0
8
10
0
10
10
0
8
10
0
9
10
0
8
Features (10%)
10
0
7
10
0
10
10
0
8
10
0
5
10
0
7
Specs Summerlite Flicker 40 UL Revelation 20 ZPacks Classic Marmot Phase 30
Style Hooded Mummy Center zip mummy bag or unzipper to be quilt Quilt Hoodless mummy Hooded Mummy
Manufacturer Stated Temperature Rating 32F 40F 20F 20F 30F (EN Comfort = 42F)
Measured weight, bag only (ounces) 19 oz 19.1 oz 20.9 oz 20.3 oz 18.3 oz
Claimed weight from manufacturer (ounces) 19 oz 20 oz 20.19 oz 19.8 oz 17.6 oz
Stuff Sack Weight (ounces) 1 oz 0.8 oz 0.6 oz 0.9 oz 0.9 oz.
Stuffed Size 6" x 12" 7" x 10" 7" x 12" 6" x 12" 12" x 7"
Fill Weight 10 oz 8.4 oz 13 oz 13.1 oz 8.5 oz
Fill Power 850+ goose down 950+ Goose Down 850 Downtek 900 fill Certified 850 fill with Down Defender treatment
Construction Continuous baffle Continuous baffles U shaped baffled quilt Vertical upper baffles and horizontal lower baffles, box baffle construction Smooth-Curved Baffles
Shell Material 100% nylon ripstop Pertex Endurance UL 10D nylon fabric .70 oz/sqyd (23.7 g/m2) Ventum Ripstop Nylon w/ DWR 10D Pertex (100% nylon ripstop)
Shoulder Girth (inches) 59" 62" 55" 61" 60"
Hip Girth (inches) 51" 48" 55" 61" 58"
Foot Girth (inches) 38" 39" 55" 35" 45"
Zipper Length Full length Full length center zip 1/3 length at bottom 3/4 length Full length two-way
Sizes 5'6", 6', and 6'6" Regular, long, and wide Short/regular, regular/regular, regular/wide/ long/wide Slim, standard, and broad (girth) short, medium, long, x-long and xx-long (length) Regular, long
Temp Options ( degrees Fahrenheit) 32F 20, 30, 40F 10, 20, 30, 40F 10, 20, 30, 40F 30F

Our Analysis and Test Results

We felt it was warmer than most of the other bags rated similarly, and could probably push it into the 20°F range if you are feeling lucky. Although you feel the ultralight shape a bit during the night, we think that the warmth-to-weight ratio is excellent, and enough to deserve the Editor's Choice for a Mummy Sleeping Bag.

Performance Comparison


The Summerlite kept us warm and dry on a rainy overnight in the Canaan Mountain Wilderness.
The Summerlite kept us warm and dry on a rainy overnight in the Canaan Mountain Wilderness.

Warmth


On a spring climbing trip to the Utah Hills, when nights were around freezing, the Summerlite kept our lead tester warm and toasty without supplementing much other clothing, something other ultralight bags and quilts don't often provide. The full zip and hood allow the full burrito option the way any traditional mummy bag would, which will always be at least slightly warmer than a quilt, especially for those who tend to toss and turn at night. Except on the coldest, windiest nights in this bag, we had to keep it at least slightly unzipped to vent the heat. Although Western Mountaineering doesn't do EN ratings, we think that the 32-degree Fahrenheit rating is more accurate than some of the other bags in the review.


Part of the reason the Summerlite is so warm is because of the continuous baffles. Unlike the Western Mountaineering Highlite, there's an unbroken four-inch layer of down separating the two nylon shell fabrics. This eliminates cold spots and allows the ten ounces of down to work together, minimizing the need for more fill. The tighter cut also eliminates dead air space in the bag and allows the Summerlite to do more with the ten ounces of 850+ down fill. Perhaps the only bag warmer (proportionally for its rating) in the review is the Zpacks 20 Degree.

The Summerlite fluffs up to a warm 4-inch fill and is one of the toastiest bags we tested.
The Summerlite fluffs up to a warm 4-inch fill and is one of the toastiest bags we tested.

Weight


For a full zip, hooded mummy bag, the Summerlite does pretty well in this department. It's not the absolute lightest mummy we tried; the Highlite and the Marmot Phase 30 are lighter, but it isn't much heavier than either while delivering more warmth. In fact, for an extra .07 ounces, we felt that the Summerlite was a good deal warmer than the Phase 30.


The Summerlite weighs within half an ounce of the Feathered Friends 40 UL and the Katabatic Gear Palisade 30. We think that for the same weight, the Summerlite delivers a bit more on warmth. Still, there are lighter bags in the review if weight is the primary consideration.

The Summerlite doesn't pack down as well as some of the other bags  and at 19 oz it's about middle of the road for weight.
The Summerlite doesn't pack down as well as some of the other bags, and at 19 oz it's about middle of the road for weight.

Comfort


In the ultralight sleeping bag game, there are three main categories: warmth, weight, and comfort. You get typically two of those categories at the cost of the third. For the Summerlite, Western Mountaineering decided to sacrifice a roomy fit to achieve something with a high warmth to weight ratio, as opposed to removing zippers and hoods like some other bags. The space around the shoulders and head was roomy enough for our 5'8" tester, but the footbox felt especially tight up to the knees. For those, like our main tester, who tend to spread out and roll a lot while sleeping, this wasn't as comfortable. The Summerlite might not be an issue for more still sleepers, but it is a consideration if you plan on keeping things like water bottles or spare clothing in your bag at night.


We do like the fabric, and there isn't anything that was poorly placed, like the drawcords or velcro. This sleeping bag feels the way sleeping bags should; like a big warm down hug. Although the hood wasn't quite as deep as we liked, the oval shape allowed for side sleepers to roll and not end up trying to breathe through nylon all night.

The WM Summerlite saves weight by shaping the bag slim in the legs and feet.
The WM Summerlite saves weight by shaping the bag slim in the legs and feet.

Versatility


Like any full zip mummy, the Summerlite is really versatile. You can unzip it when it is hot, or burrow down into it when the temps drop. The Marmot Phase also has a full-length zipper, which, along with the Summerlite, allow for better venting than the Patagonia 850 and Highlite.


The warmth allows this bag to be used early spring or late autumn and could work for an entire through hike such as the PCT, especially if you incorporate a clothing system into the mix. Because it vents to well, our testers are happy to use this bag on warm summer nights as well.

The Summerlite did pretty well with repelling condensation  and even a deluge from a water bottle without the fabric wetting out much.
The Summerlite did pretty well with repelling condensation, and even a deluge from a water bottle without the fabric wetting out much.

Features


The features of this Western Mountaineering bag are pretty well thought out. We like the full-length, burly #5 YKK zipper, and the small strip of stiffer fabric next to it to avoid being sucked into the teeth, which was nice when we were adjusting it in the middle of the night. We like the offset drawcord of the hood that didn't get in the way, but we did think that the hood was a bit shallow, and didn't allow for as much coverage as some hoods.


The stuff sack is adequate, but it isn't a compression sack or drybag, which are excellent additions other bags provide. However, we acknowledge that many thru-hikers will leave the included sack, whether it's a stuff or compression type, at home to save weight, preferring to stuff an unwrapped sleeping bag into their packs. Overall, with some small design tweaks, this could have scored a bit higher.

While we liked most things with the Summerlite  we wished the hood was a little deeper.
While we liked most things with the Summerlite, we wished the hood was a little deeper.

Best Applications


This bag could be great for those who value weight and warmth over a roomy cut, like smaller bodied thru-hikers. We would happily use this bag on summer alpine climbing trips or long through hikes. Less restless sleepers or smaller folks will get more use out of this bag than larger folks, who might look at the similar but larger Western Mountaineering Megalite.

Western Mountaineering thoughtfully integrates a stiff strip of fabric to avoid zipper snags.
Western Mountaineering thoughtfully integrates a stiff strip of fabric to avoid zipper snags.

Value


The Summerlite isn't the most expensive bag on the list, but at $410, it's pretty close. Still, you're paying for quality, and the Summerlite delivers. We like this bag, and other mummy bags in the review are almost as expensive, but if you're looking to save money, a quilt might be a better option.

Conclusion


The Western Mountaineering Summerlite does many things well. It keeps you really warm, packs down fairly well, and doesn't add too much to your base weight. To keep the warmth and weight down, the cut is fairly slim, which might impact larger folks or restless sleepers. Still, the Summerlite performed at the top echelon of bags we tested, and if you're looking for a traditional sleeping bag for an ultralight setup, we think the Summerlite is a great option, enough to win the Editors' Choice Award.


Ethan Newman