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Hands-on Gear Review

Western Mountaineering Summerlite Review

Ultralight Sleeping Bag

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Price:   $390 List | Sale $389.95 online  —  Compare prices at 3 resellers
Pros:  Very light, simple, warm, fully baffled construction, full-length zipper increases versatility
Cons:  Fixed girth snug for larger hikers, other mummies have more comfortable hoods
Editors' Rating:     
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Manufacturer:   Western Mountaineering


The Western Mountaineeering Summerlite, rated at 32 degrees F, is a feather light, fully-baffled, traditional mummy bag. While most of the products in our Ultralight Sleeping Bag review forgo a hood and other features common to mummy bags, the Summerlite has them all: a full length zipper, a draft tube that backs it, and a warm hood. While most ultralight backpacking enthusiasts prefer quilts or bags that eliminate the hood, it's not everyone. One of our testers has thru-hiked the Triple Crown of Hiking with a Summerlite, and it continues to be his go-to bag for all three-season backpacking.

Of the two ultralight hooded mummy bags we evaluated this year, our testers much prefer the Summerlite to the Mountain Hardwear MTN Speed 32. We found the Summerlite warmer, more durable, and more versatile due to the full length zipper. You'll find a few more very light mummy bags tested in our review of Backpacking Sleeping Bags.

RELATED: Our complete review of ultralight sleeping bags

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Analysis and Hands-on Test Findings

Review by:
Brandon Lampley
Review Editor

Last Updated:
November 1, 2015
The Summerlite was the fourth warmest ultralight bag we tested this year. The construction quality is top notch and the features increase its warmth. This is a very light, fully-baffled mummy bag with a hood, and a durable full-length zipper.

How to Get It:
The Summerlite is available from several online retailers and many outdoor stores.

Use our price comparison tool to find the best price!

Performance Comparison

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Take great care of your bag and it will take good care of you! The Summerlite is a top quality traditional mummy bag that will last for years with proper care.


We awarded the Summerlite an 8 out of 10 in our updated ultralight review for warmth. In near freezing temperatures, our testers slept warm enough in this bag while wearing a mid-weight base layer top and bottom. Our lead tester, who's 185 lbs, finds that wearing more than a baselayer is very constricting in the narrow confines of this bag, and warmth is not gained because the bag's down insulation is compressed from the inside. But another of our testers, who's six feet tall and about 145 lbs, loves this bag in lower temperatures. He has enough room to wear an insulated jacket inside.

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If you are a side sleeper, this fully baffled bag will be warmer than the Mountain Hardwear MTN Speed, which uses sewn-through construction on the bottom.

While back sleepers will find this bag similar in warmth to the Mtn Speed, the Summerlite is much warmer for side sleepers and contorted positions. It is fully baffled, as opposed to the Mtn Speed which uses sewn-through construction on the bottom to save weight. All this said, we find closed footbox quilts like our Editors' Choice Katabatic Gear Palisade 30 deliver the best warmth-to-weight ratio for ultralight sleeping.

Weight & Packed Size

Our standard length test model, appropriate for folks up to 6 feet tall, weighed in at 18.3 ounces, and the included stuff sack weighs .9 ounces. This makes it one ounce heavier than the ZPacks 20 Degree, the highest scoring mummy bag in our ultralight review. The Zpacks eliminates the hood, and uses a half length zipper. Paring away these features allows ZPacks to build a mummy bag that is both warmer and lighter than the Summerlite. Packed away in the included stuff sack, the Summerlite measures 6 x 11 inches.

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Our Summerlite test bag weighed in at 18.3 ounces, one of a few products we tested that was LIGHTER than the manufacturer claimed weight.


Versatility is not a strong point of a traditional mummy bag. While the full length zipper on this model allows you to open it up down to the footbox for hot summer nights, the fixed girth when closed makes it difficult for all but thin hikers to add warm clothing for cold nights. The Summerlite received one of our lowest versatility scores.

The most versatile ultralight sleeping bags are fully-opening quilts. Within this category, our Best Buy Award winner, the Enlightened Equipment Revelation 20, is our favorite.


While we find the hood of the Summerlite comfortable as far as hoods are concerned, most of our testers prefer a quilt or mummy bag that eliminates the hood. And as described above, the cut of this model is quite slim. Our larger testers find it restricting, while thinner folks are more comfortable inside.


This feather light hooded mummy uses a full-length #5 YKK zipper with pulls at both the top and the bottom so you can ventilate at the foot if desired. The warm draft tube that backs it for warmth it stiffened to prevent zipper snags, and we found the operation smooth.

A non-stretchy cord provides the adjustment of the hood at face and brow to seal in warmth. The cord lock here is free-floating, a feature that some prefer since it facilitates a quick exit from the bag. Finally, 360 degree continuous horizontal baffles hold the down in this model and the "Made in the USA" tag at the bottom doubles as a single hang loop.

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A full-length, smoothly functioning, and durable zipper makes this bag more versatile than most ultralight mummy bags. It is also backed by a draft tube the entire length to seal in warmth.

Best Applications

The Western Mountaineering Summerlite is a great choice for three-season backpacking and thru-hiking. We found it warm enough into the mid 30s while wearing only a base layer, and smaller hikers have room in its fixed girth to add warmer clothing for colder nights.


If this bag is a good fit for what you seek in an ultralight sleeping bag, then $405 is a good deal. One of our testers is approaching 10,000 miles of hiking with his Summerlite, and it is still going strong. Western Mountaineering is known to build very durable products.


The Western Mountaineering Summerlite is a durable and warm three-season sleeping bag. It is one of the lightest hooded mummy bags that will keep you warm in near-freezing temperatures. However, to keep the weight light while still offering great features like a full length zipper back by a draft tube, Western Mountaineering designed this bag with a slim cut. We recommend it to relatively thin hikers.

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Staying warm in the Western Mountaineering Summerlite. This top-of-the-line mummy bag has a good warmth-to-weight ratio, but suffers in versatility.

Sizing, Accessories, & Other Versions

The Summerlite is available in three sizes:
Short 5'6ʺ, Standard 6'0ʺ, Long 6'6ʺ

Western Mountaineering makes many excellent sleeping bags. The Ultralite, rated at 20F, is also very popular with thru-hikers.

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Western Mountaineering Ultralite
Fully baffled 20 degree bag
  • Cost - $485
  • Weight - 1lb 13oz
  • Shoulder girth - 59"
  • Fill power - 900
  • Rating - 20 degress

Western Mountaineering Highlite
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Sewn-through quilted construction
  • Cost - $340
  • Weight - 1lb
  • Shoulder girth - 59"
  • Fill power - 850
  • Supremely lightweight, hyper compressible summer weight down sleeping bag
  • Rating - 40 degrees

Western Mountaineering Versalite
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  • Cost - $575
  • Weight - 2lbs
  • Shoulder girth - 62"
  • Fill power - 850
  • Rating - 10 degrees
Brandon Lampley

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Most recent review: November 1, 2015
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