Big Agnes Hahns Peak SL -20°

2 reviews
5-star:   1
4-star:   0
3-star:   1
2-star:   0
1-star:   0


fall 2010 regular long
Weight 3 lb 6 oz / 1500 g 3 lb 10 oz / 1600 g
Fill weight 2 lb 0.5 oz / 921 g 2 lb 3 oz / 990 g
Temperature rating -20 F / -28.9 C
Fill 800 fill down
Shape mummy
Max user height 5 ft 10 in / 180 cm 6 ft 6 in / 200 cm
Shoulder girth 67.5 in / 171 cm 72.5 in / 184 cm
Hip girth 64 in / 160 cm 69 in / 180 cm
Foot girth 43 in / 110 cm 44 in / 110 cm



This bag is different since it doesn't have down on…

Rating: rated 3.5 of 5 stars
Source: bought it new
Price Paid: $300 in 2010


This bag is different since it doesn't have down on the bottom side of the bag, but instead room for a fitted sleeping pad.


  • Lightweight and packs small
  • Reasonable durable


  • Included sleeping pad is heavy

I have used this bag since 2010 for winter hiking and in most cases in the Adirondacks, but also on the West Coast but then in a bit warmer temperatures. I've experienced temperatures down to -20°F, which I think is the limit for what I'd feel comfortable in. I normally just sleep in a thick fleece base layer when sleeping in cold weather. 

I've never really taken the included sleeping pad into use since it's thinner and heavier then the all season Them-a-Rest that I'm currently using. This can create problems during the night when I turn from one side to another, I might not notice that an area with no down has been exposed. During really cold nights I try to sleep on my back and stay as still as possible. 

Since the lowest temperatures I've experienced is -20°F (-29°C) and I'm always a bit worried that it will dip even a bit lower, I've been thinking about buying a -40°F bag. But a -40°F bag is around 4.5-5 lbs and this one is 3 lbs 14 oz without the pad.

I've used a vapor liner on one trip. I normally don't go out for more than four nights and don't feel I need a vapor liner for shorter trips, but the bag will feel quite clammy once I'm back home from a four-night hike. 

I'm 6'2" and 170 lbs and the long version feels perfect in length and width. The zipper is okay. 

The bag packs very small and is easy to compress (it's made out of regular thin nylon).

I'm not sure about its loft compared to other -20°F bags. I wouldn't think it's on the large side, maybe medium or small for a -20°F bag. 


I was very reluctant to pay so much money for a sleeping…

Rating: rated 5 of 5 stars
Design: mummy
Fill: 800 fill down
Temperature Rating: -20 F
Weight: 2 lb 15 oz
Price Paid: $475

I was very reluctant to pay so much money for a sleeping bag, but I told myself that if I did not get a good night's sleep, I would suffer.

I went to Argentine Patagonia this winter (May, June) and experienced anything from 40 F to near 0 F. This was still above the technical rating of the sleeping bag, but I was super impressed with this bag in all aspects. It was lightweight, packed into a tiny ball and proved to serve as a warm bag.

We slept on cold rocks and many feet of snow and I never had problems of staying warm. In fact, I had to resort to sleeping in only a shirt while my tent mates would be in thermal underwear and socks.

The only downside of this bag was that the built in pillow sack became unstitched in just a few threads because I would catch it with my arm while turning in my sleep.

I highly recommend this bag and trust the temperature ratings of Big Agnes.


hi Travis. i want to ask you... how was your sleeping condition as far as humidity goes? were there any damp and humid conditions?? if so how was the bag in that condition? i want to buy this bag but it isn't treated goose down... yet is 800 fill power so it is a high quality bag... i never own a Dry tek(treated feather) bags before... please give me your opinions on the damp conditions such as rainy and high humidity conditions. thanks~

12 months ago

also please tell me your sleeping pad. what kind of sleeping pad have you used?? do you think that i could use 3 season sleeping pad for winter condition? say -0 and below???

12 months ago

Manufacturer's Description

Visit Big Agnes's Hahns Peak SL -20° page.

Retailers' Descriptions

Here's what other sites are saying:

The Big Agnes System is different than the traditional sleeping bag on top of a sleeping pad. With Big Agnes, the pad slides into an integrated sleeve on the bottom of the bag, and the top two-thirds of the bag is insulated in the traditional style. We el

- Teton Village Sports

800 Fill Goose Down and 28 oz of fill weight combine to make the Big Agnes Hahns Peak SL a comfortable high alpine mummy sleeping bag. Draft collars around the neck, zipper and pad connection point keep out the cold air and seal in warmth. At only 3 lb 8 oz and a compressed size of 8x9 in, the Hahns Peak sets the standard for high alpine sleeping comfort. Like all Big Agnes Sleeping Bags, the Hahns Peak requires a pad. We recommend a Two Track mummy pad. for the regular get a 20x72x2 in. mummy pad and for the long you'll need a 20x78x2 in. pad.


On Sale. Free Shipping. Big Agnes Hahns Peak SL -20 Degree Sleeping Bag FEATURES of the Big Agnes Hahns Peak SL -20 Degree Sleeping Bag Integrated half pad sleeve design Mummy shaped bag Pillow Pocket Liner loops 70in./178cm YKK #5 zipper 48in./122cm YKK #5 zipper, Pitchpine Mate together left and right zip bags Mesh storage sack and nylon stuff sack No-draft collar, No-draft wedge, No-draft zipper (not available on Horse Thief and Pitchpine) SPECIFICATIONS of the Big Agnes Hahns Peak SL -20 Degree Sleeping Bag Temperature Rating: -20deg F / -29deg C Fill Type: 800 Down Pad Size: 20in. / 51 cm Pertex Nylon shell fabric Nylon Taffeta lining Insotect Flow Construction Quilted construction, Pitchpine 800 fill Down SPECIFICATIONS for Regular Bag Weight: 3 lbs 6 oz / 1531 g Fill Weight: 32.5 oz / 921 g Compressed Size: 8 x 9in. / 20 x 23 cm Stuff Sack Size: 9 x 20in. / 23 x 51 cm Fits up to: 5'10in. / 178 cm SPECIFICATIONS for Long Bag Weight: 3 lbs 10 oz / 1644 g Fill Weight: 35 oz / 992 g Compressed Size: 8 x 10in. / 20 x 25 cm Stuff Sack Size: 9 x 20in. / 23 x 51 cm Fits up to: 6'6in. / 198 cm

- Moosejaw

Integrated half pad sleeve with unique design keeps you securely attached to the pad from the hips up while allowing freedom of movement for your legs more like a traditional mummy bag Never roll off you pad again Half pad sleeve with adjustable strap holds ANY 20 wide rectangular or mummy shaped pad Mummy shape decreases weight packed size Recycled mesh storage sack nylon stuff sack included Built in pillow pocket holds a fleece or Big Agnes pillow Interior fabric loops for sleeping bag liners 70 YKK 5 zipper Mate together any of our left and right zip bags with the same size zipper Nodraft collar seals around neck to keep cold air from sneaking in Nodraft wedge insulates the connection betwen the bag and the pad Nodraft zipper tube insulates along the length of the zipper Shell Fabric Pertex Quantum ripstop nylon Featherweight high threadcout fabric that is soft as silk with a small packing volume WR surface treatment to repel water Lining Ultralight high thread count soft nylon taffeta


Big Agnes Hahns Peak SL -20°


The Big Agnes Hahns Peak SL -20° is not available from the stores we monitor. It was last seen August 15, 2014 at

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