REI Co-op - Magma 15

A 15 degree bag will keep you warm at 25 degrees. You'll want an additional quilt or a lighter bag for the coldest nights. If you need to backpack it in, down is worth it. I have an REI 15 degree down bag. I bring a 30 degree down bag as a blanket when it gets to the low 20's. I have a -20F down bag, but it takes up too much space if I don't really need it. If you're close to your car, synthetic bags are much cheaper.

Gnarly! Sounds like some top tier "type B" fun. Early on in backpacking, after several uncomfortable, borderline worrisome nights sleep in my 20°f Kelty bag I learned the advertised temperature ratings of sleeping bags are actually the "survival rating,", meaning you won't lose any appendages to the elements. The comfort rating is always significantly warmer than the survival rating and you often have to research equipment in advance to find thst figure. I'm PNW-based, and personally, fall-winter I use a rei magma down 15 bag & neoair xtherm pad. I might not ook like Jeremiah Johnson all bundled up but I sleep like a baby. Risking death chasing the bushcraft aesthetic in a cold, damp environment isn't worth it if you lack the ability or materials to craft an adequate sleep system.

Did you get the new magma 15? I got each the 30 and the 15 and while I love them, I feel like there’s such a huge gap in temp conditions. The 15 I’ve slept in down to about 22 and it was WAY too warm still. If I slept in the 30 down to 22 I’d undoubtedly be cold. I just think it’s bizarre they came out with two bags that seemingly have a huge gap.

Oh nice! I’m kind of jealous of that 15. I’ve used it before and it’s really awesome. When they made the new ones they started making them unisex, so the lower limit became more of the men’s comfort rating and the actual number became more of the women’s. Your 15 fills the gap in talking about a whole lot better. Granted I did get the wide version and it’s so so comfy so I guess I’ll deal

After years of budget backpacking, I sprung for the magma 15 last fall and couldn’t be happier with it. I find it very comfortable at sub 20°. My only complaint is the size. It’s a bit large but not a dealbreaker

Something to keep in mind is the comfort rating vs “lower limit) rating (are we all confused yet?! 😂). For that bag it’s 30f (comfort) and 20f (lower limit). I personally run cold and have a down sleeping bag (REI Magma) that’s comfort rating is 21f and lower limit is 9f and find it perfect WITH layers AND a hearty meal before turning in for the night. Overkill in the summer but for me it’s perfect. Do you know if you sleep cold or warm? What is your budget? Otherwise enjoy Yosemite. It is absolutely beautiful.

That is a dope sleep is pad. I don’t know if I am any help 😂 I’m a big fan of the REI Magma 15 since it’s all I have used and it hasn’t done me dirty BUT it is hella expensive. Which Big Agnes were you looking at? The one that looks like it attaches to your pad?

Three seasons where exactly? A better question may be will your trips ever have nights below freezing? You did say "at least..." so I imagine yes? If so, I'd look at the REI Magma 15. If not, try the Magma 30, or Magma quilt. There are plenty more options from really good companies, but since this is a REI subreddit, I thought I'd mention them. Make sure you have a good, warm sleeping pad. And I'm a fan of liners. Keeps the bag clean, and add some warmth too.

So very many choices. I've always found [Outdoor Gear Lab](https://www.outdoorgearlab.com/topics/camping-and-hiking/best-backpacking-sleeping-bag), as well as [Switchback Travel](https://www.switchbacktravel.com/best-backpacking-sleeping-bags) give some of the most honest, accurate comparisons. I may not agree 100%, but I mostly do, and when I don't, it's for minor reasons. Plus, they don't accept ads, and aren't "influencers". In fact, they buy all the gear themselves! You need to ask yourself some questions though: * How light do you need it? Are you willing to pay another $100 to shave maybe 2 ounces? * How much room do you need? Some are fairly snug mummy bags (MH Phantom, Thermarest Hyperion), some are more roomy (an REI Magma 15 comes in a wide, for example). * Do you like a lot of features? A Nemo Disco has "thermo gills" which help regulate temp, plus a nice draft collar, plus are roomy...all of which comes at a cost in it weighs more. * Still not enough room? Try a quilt. But quilts down below about 20 degree ratings don't make much sense. * Presuming you go down (recommended) most spray their shells with DWR. Some also treat the down (Sea to Summit, Thermarest, others) some don't by purpose (Feathered Friends, Enlightened), but you can do it on your own washing the bag in Nikwax Down Proof, or spraying it with TX Direct. Some bags even have GoreTex shells for extreme conditions. As you can see, it goes on and on. You could go down a real rabbit hole.

A tent that was 2 lb or less and a sleeping bag that is fairly light as well. I went with Big Agnes fly Creek and the magma 15 by REI. It's shaved off 2 to 3 lb at least and I have more space my backpack.

Its not the new one. When REI had their clear out of the model they've been selling the last few years, I bought 3 30s and one of the 15s. Got them for under 80 or so each.

It is a very nice bag. Not huge when stuffed down...I'd love another. Check Facebook Marketplace...I see them occasionally there.

30 for lower elevations summer...15 for high elevation for me every time.

Just switched to[ ](https://wisechoicetoday.blogspot.com/2025/05/rei-magma-15-sleeping-bag.html)[this sleeping bag](https://wisechoicetoday.blogspot.com/2025/05/rei-magma-15-sleeping-bag.html). Light, packs down tiny, and still kept me warm below freezing.

With backpacking, many folks including myself prefer quilts. Especially with down so that they weigh and pack down to almost nothing. So this is worth looking into if you choose to. That being said, things to look for when buying a sleeping bag are comfort rating, material(down/synthetic), any specific features and build quality. Example: You can get a synthetic Walmart 10* Ozarks sleeping bag that's comfort rated for 10* for 40 bucks or REI Magma 15 which is actually comfort rated for 21* for 430 bucks. Both these bags are ISO rated for their comfort rating. Both of them will work in temperatures down to freezing and keep you alive and comfortable. Then what's the difference? Walmart bag is bulky and heavy. REI is down, so it's much lighter(half the weight), better features; like no snag zippers, pockets, draft collar etc. So it comes down what features you want, do you have a target weight for your backpacking gear and what your budget is... Last but not least, how cold is it going to get where you are looking to camp. Here are a few more bags to consider: https://www.nemoequipment.com/collections/mens-ultralight-sleeping-bags/products/coda-genderless-endless-promise-down-sleeping-bag https://zpacks.com/products/classic-sleeping-bag?aff=66 Some of these bags might be out of your budget but stuff like REI and nemo go on sale multiple times a year. You missed a pretty big one in Nov.

I would definitely recommend a warmer bag, especially if you are in Canada, like maybe 20-30 degrees. I have a mummy bag but it's a bit oversized (REI) so I can move around a bit more.

Featherstone tent, REI sleeping bag from their used gear section. Edit: took a WELL used featherstone granite 2p tent on the Great Divide Bikepacking route. 69 consecutive nights of use in all types of weather. Rain, snow, high winds. It was Bombproof. It still had tons of life left at the end. Picked up a used REI magma sleeping bag from their used gear section and used it for 60 consecutive nights of bike touring in South America. I still have it and it still works great.

If you want light weight, small packed size and good temp rating… the magma by REI is the best bang for the buck… because of the size choices. If that is to much… The Trailmade is super inexpensive, and comes in a variety of lengths and widths. It is not as light, nor as compactable. If you were in the store, I would ask a whole bunch of questions… side, back or stomach sleeper? Do you roll? Where do you normally get cold? What is the likelihood of the bag getting wet? Etc… etc… I’d ask because there are so many options and each kind of sleeper works with a different kind of bag. But if you want the lightest and most compact… and best bang for the buck… the magma is the way to go? also do not forget to buy or make a liner. No sleeping back should be used without one!

My advice: NEMO women's Disco 15. First off, sleeping bag temps (ISO/EN) are rated for slight discomfort. If you want to be mostly comfortable at 30F, you get a 30F bag; if you want to be warm and toasty, you get a 20F bag. If you think temps may drop into the 20s but may realistically be 30s, you should get a 20F bag; if it hits 20F, you're fine but you'll otherwise be toasty. Women's bags are rated at the Comfort rating which is toasty and nice for a warm sleeper, slightly uncomfortable for a cold sleeper - which is the assumption for women. Also what it sounds like you may be: a "cold sleeper"/someone who likes to be warm at night. Know that you can - and should - try other gender bags for fit as you may find better fits across genders. But keep in mind there is ~10F temp difference between men's fits and women's fits (men's will be colder for cold sleepers, women's will be warmer for warm sleepers) and so don't just trade 30F for 30F. In your case, use the "Comfort Rating" as your slight discomfort temperature and adjust from there. Know also that this may work against you price-wise; they do not price based on fill, they price based on advertised temp. So a women's 30 will be the same warmth as a men's 20, but will be priced as a 30, not as a more expensive 20. So the Magma and the Disco may not be warm enough for what you're looking for. Of the listed bags, they'll fit in order of how you listed them: Disco will be the widest, then Big Agnes, then the Magma. The Magma is a true backpacking mummy and won't be ideal for a side sleeper. The Disco has extra space in the shoulders and hips which are ideal for getting on your side in the bag. So for a cold sleeper who sleeps on their side and is likely to have some 20F but maybe mostly 30F nights - NEMO Disco 15. Should check all of the boxes. The one big difference between the NEMO and the Magma is down fill power, which also impacts compressibility and weight. Magma is an 850 while the Disco is probably around 650-700. If you want a similar fill power bag go with the Riff 15. 850 fill down also warms up quicker because the feathers are smaller. It will also probably be more on par price-wise with the Magma. The Riff has all the same features as the Disco though may have a slightly slimmer shape. If you can, go to your local REI and get in each one to see which are comfortable and which are not. But based on the info you've given, I'd suggest either a Women's NEMO Disco 15 or NEMO Riff 15.

Remember that you can move your legs around all you like by moving the sleeping bag with them. I sleep in the fetal position in a very narrow bag because I curl the bag into that position with me. (I have REI's magma and it's extremely toasty)

I like the REI Magma

Try a quilt. I recommend the sierra designs 20(?) or rei magma

I have also gone to ground. I took my quilt with me and love it. I have used a sleeping bag, and it just isn’t as nice. My quilt is the Warbonnet Diamondback, and my sleeping bag is the REI Magma. I have never had cold sleeping problems, I just enjoy the quilt more.

I went with the Magma and a Nemo Tensor wide sleeping pad. Thanks for the recommendation

The REI Magma mens/women's bags zip together and are wonderful. They have both 15⁰ and 30⁰ bags.

Interestingly, I hated my Magma. I don’t feel it performed as well as advertised. Got an Enlightened Equipment quilt and have been much warmer.

My order of preference, without prying more info out of you would be: 1. Magma 2. Radiant 3. Nemo … anyone giving you numbers after the name of the bag is guessing because you never mentioned what temperature rating you need and what geography we are talking about. In terms of r-rating we would need to know what mattress pad you are shlepping too…