15 degree sleeping bag

Although I'm a WM fangirl, if you want lighter, you could get a ZPacks sleeping bag (probably the 10F model to be equivalent to the Alpinlite).

ZPacks' "regular" width will be the lightest, but it will be really narrow; depending on your height, you'll have several lengths to choose from, and of course, there is no hood, so you might want to add a down hood.

You could save a fair amount with a Zpacks 10 degree bag. It will weigh anywhere from about 500 to 800 grams depending on the length and width configuration.

Edit: Hehe, Valerie beat me to it!

What about the Katabatic Gear Sawatch ? Is that warmer than the Zpacks?

Katabatic is a quilt, not a sleeping bag.

The WM Alpinlite is the finest 20 degree bag made. I wear size XL shirts and the wider cut of the Alpinlite (64" shoulder) is really nice. And the entire Extremelite shell only weighs 12.6 oz.

Even the ZPacks Wide is still just 61" shoulder girth, and their X-Wide is 66", almost too much for 99% of backpackers.

But when it comes to quilts, Katabatic is hands down the best. The shell material isn't quite as light as EE quilts, but they're superior. IMO the upper body shape and neck closure of the Katabatric quilts are way better.

I'm a Western Mountaineering Fan-boy. I just haven't ever had a single problem with any of their bags and have successfully pushed them well below their ratings over and over again. I own four of them now. They're pricey. But, so are the best quilts.

I tried a couple of my buddy's quilts to see what I might have been missing. I guess that I've just been using traditional sleeping bags for so long that I never adjusted to what seemed like the extra hassle of strapping a quilt to my pad and making adjustments during the night when I woke up to an air leak, due to my side sleeping and toss and turn habits. I really liked the idea of the extra weight savings and the ease of venting with the quilts in the summertime. But, I just couldn't grow to love them during the shoulder months in the Rockies.

Since I had already invested in a Summerlite, I just couldn't bring myself to blow the money on a top notch summer quilt. Otherwise, I would probably have made the switch to quilts for the warmer months. I usually end up opening up my Summerlite and using it like a comforter in the summer anyway and it's a pretty light load at 1lb 3 ozs. anyway.

I keep coming back to my WM Alpinlite (1 lb. 15 ozs.) for trips with an expected range of 10-32 degrees. If you don't need the extra space (and/or are a gram weenie like most of us on here), the WM Ultralite (1 lb 13 ozs.) will save you another two ozs. I just felt like I was in a straight jacket, after the luxury of the extra space that I get from my Alpinlite. I'm a side sleeper and it's so great for that. So, I let my Ultralite go to my oldest son a couple of years ago and haven't regretted it a bit.

Check out the Feathered Friends bags also. They are great quality and a little less expensive. You also have a choice of fabrics.

WM fan here too. Been using an Apache MF 15 degree for years. Highly recommend it. Use a Summerlite in warmer weather. Some may not like the heavier Microfiber series outer fabric but I actually prefer it to the Extremelite series, seems to repel water and breathe better in my experience. Temperature rating spot on for an average person but I tend to sleep cold, find it ok to around 20 with baselayers.

Similar weight and fill to the Alpinelight but has the trimmer fit of the Summerlite and Ultralite and rated 5 degrees warmer. I am a little under 6ft and weight around 145lbs and find it to be a perfect fit but would go roomier if any larger.

Marmot plasma 15. Looks pretty promising. Will Wood (YouTuber with some good videos) used one for his entire AT thru last year. He's hitting the PCT this year by I'm not sure if he's using the same bag again.

Anyway, seems really nice but I don't know how the price compares to WM

http://marmot.com/products/details/plasma-15-new

I've made the transition to (EE) quilts, but used and loved a WM Megalight for the previous ten years. I've never seen a better designed, constructed or higher function sleeping bag than WM.

I'm not saying there isn't anything out there that compares favorably to WM, but I would not buy any other bag.

Oh yeah…I still have the Megalight and it is as perfect today as it was 10 years ago.

I want to go as light as possible without comprimising warmth.

A.C., you don't have a lot of posts on BPL thus far and no geographical info is provided in your profile, so there isn't a lot to go on with regards to sleeping gear recommendations.

Maybe you already know this or maybe not, but especially as the temperatures drop you want to think in terms of sleep systems and how you can combine your clothing, sleeping bag/quilt and sleep pad for the lightest possible combination. You can have the best bag or quilt on the planet, but without an adequate sleep pad(s) underneath you can still end up cold and miserable.

This past winter I did a lot of experimentation to see what works for me down to 0°F and a little below that. I was so comfortable at a few degrees below 0°F that I can confidently say that my system will work down to about -10°F. But again, that's for me. Learning what works for us individually is an evolutionary process so despite all the advice you receive don't be surprised if what you end up with a few years from now is a lot different from what you start with.

My system consists of an EE Enigma 20°F (yes, +20), a Thermarest Neoair Trekker 47"x25" and a full-length 1/4" CCF foam pad, 21"x72" and an Exped pillow. I put my pack in the foot area with the CCF pad over it. I like the 25" width of the Neoair Trekker because my elbows don't fall off and it is more comfortable, and also the only torso-length/wide air mat I could find. Wearing a hooded down jacket and pants for sleeping is an integral part of the lightweight system, and for that I used an Eddie Bauer Stormdown hooded jacket and Montbell UL Down TEC pants, which are necessary anyway at such temperatures. Although I am only 5'9" I got the long/wide version of the Enigma to accommodate the extra bulk of the hooded down jacket and the down pants. When I went to sleep for the night, I was wearing everything I brought except for some thicker gloves and shells. I'm a toss-n-turn sleeper and never got cold.

The Enigma weighs 625.9g (with 2 elastic straps), Neoair Trekker 369.6g, CCF pad 218.6g and Exped pillow 55.5g (with strap) for a combined total of 1269.6g, which is 2.79lb and quite respectable for a winter sleep system. I also added an extra elastic strap at 10.5g which brings the total up to 2.82lb. But I found the extra strap is very useful for keeping the pads aligned all night with no worries.

I have a similar question, and I figured I would post here.

I live in Colorado, and it often gets around or below freezing at night in the mountains, even in the summer (climate data from Leadville at 10,000 feet is representative http://en.wikipedia.org/wiki/Leadville,_Colorado#Climate). I'm looking for a system that's good down to around 20. I don't like to be cold, but my feet are often cold with my current setup. I have a Mountain Hardware Ultralamina 15 long (EN rated at 19 degrees), which I take most of the time, and a Marmot Hydrogen Long that I don't use much because it's not quite warm enough a lot of the time. I use a full length Nemo Astro Insulated pad. I'm around 6' tall and really thin, so I prefer a longer bag, but I don't need a wide bag. I'm not interested in quilts right now.

The WM Alpinlite is often recommended as a 20 deg bag, but it's not that much different from the Versalite which is rated for 10. The total and fill weights are almost the same, so I guess the Versalite's slightly slimmer cut makes it warmer. The Feathered Friends Lark looks similar to those two. There's also the FF Hummingbird, which is significantly lighter but has significantly less fill than the WM options. Would the Hummingbird be warm enough compared to what I have, or should I go with one of the bags with more fill? It only has a little more fill than my Marmot Hydrogen, but I guess the slimmer cut means that it will be warmer since the down is spread out over less area.

Maybe my Ultralamina has lost some of its loft? I might try to wash it, but I don't know if that will help.

Should I just use the hydrogen and wear a down jacket and possibly down pants on colder nights? I would probably bring those things anyway to stay warm at camp, so it's not any extra weight. The hydrogen isn't the lightest for the warmth, but I'm only interested in upgrading if I can save a significant amount of weight, like 1lb. The Ultralamina is just over 3lb, so there's room for weight saving there.

Your situation is just like mine Matt. I use a Alpinlite and it works great. But while I hike in ultra thin shorty socks, I bring a "regular" thickness, ankle high pair of wool socks for sleeping. I find that if my feet are cold, I'm cold. In shoulder season, I'll bring down booties. 2 years ago on a Winds trip in the 3rd week of September, I pulled the down booties out of my pack at the last minute. Boy, did I regret that! Keeping my feet and head warm are my highest priorities. Maybe try the booties (or wool socks if you aren't using them already) and see if that makes enough of a difference for you.

Although light as possible may be what you're after, I would go with something that give at least a little wiggle room.

I have a long 63" bag but only need a 59" regular.
I can use it with a with a very bulky jacket when it gets really cold or I'll be sitting around camp.

Then for my winter set-up I go with the same bag and a homemade 15 ounce quilt.
The combo is as warm as most 0* bags.