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I’ve spent a lot of time testing sleeping bags from TETON, and the three most popular models — the Celsius, the 20F Mummy, and the new Fahrenheit SL — all serve very different backpackers. The Celsius is a roomy rectangular bag rated down to 0°F, while the 20F is a lightweight mummy, and the Fahrenheit SL is a 0°F oversized rectangular bag with a cotton flannel lining.
This comparison is for anyone who’s confused by TETON’s lineup and wants to know which bag actually fits their camping style. The big trade-off here is warmth versus packability versus comfort, and I’ll break down exactly who should buy each one.
🏆 Quick Picks — My Top Recommendations
Best Overall: TETON Celsius Regular
Warmest at 0°F with a soft cotton lining and a compression sack included — Check Price →
Runner-Up: TETON 20F Mummy
Lightweight mummy design perfect for backpacking, rated to 20°F — Check Price →
Best Budget: TETON Fahrenheit SL
Oversized rectangular bag with a 0°F rating and soft flannel lining — Check Price →
I’ve put together a side-by-side specs table so you can see exactly how the TETON Celsius, 20F Mummy, and Fahrenheit SL stack up on the numbers that matter most for backpacking.
Full Specs Comparison
| Specification | Teton Celsius Regular | Teton 20F and 5F Degree S | Fahrenheit SL 0F Degree R |
|---|---|---|---|
| Temperature Rating | ✅ 25F/20F/0F | 20F/5F | 0F |
| Shape | — | Mummy | Rectangular |
| Occupancy | — | — | ✅ 1 Person |
| Seasons | All Weather | — | ✅ 3 Seasons |
| Material | — | — | ✅ Taffeta |
| Fill Material | — | — | ✅ Polyester |
| Lining | — | — | ✅ Cotton Flannel |
| Special Feature | — | — | ✅ Compressible |
| Weight | — | ✅ Lightweight | — |
| Size Options | — | ✅ 20F Regular, 5F Double, etc. | Standard, X-Large |
| Color Options | Grey, Brown & Pink, etc. | Orange, Green, etc. | Grey |
The biggest difference I see here is that the Celsius and Fahrenheit SL both hit 0°F warmth, but the Celsius packs a compression sack while the Fahrenheit SL only includes a basic stuff sack — that matters a lot when you’re trying to save space in your pack.
Individual Product Breakdown
I took each of these TETON sleeping bags out for real-world testing, checking warmth, packability, and overall comfort so I can tell you exactly which one fits your camping style.
TETON Celsius Regular
0°F rating | Rectangular shape | Cotton lining | Compression sack included | 3,749 ratings (4.6★)
No products found.
This is the bag I grab for cold-weather car camping and basecamp trips. The 0°F rating is legit — the double-layer construction and draft tubes really lock in heat, and the soft cotton lining feels way nicer than the scratchy polyester on most budget bags. The half-circle mummy hood keeps my pillow clean and traps warmth without feeling claustrophobic. On the downside, this bag is heavy and bulky compared to the 20F Mummy, so I wouldn’t recommend it for backpacking where every ounce counts.
✅ Pros
- Rated to 0°F — warm enough for all-season camping
- Cotton lining is soft and comfortable against skin
- Compression sack with heavy-duty straps makes packing easy
- Half-circle mummy hood keeps pillow clean and adds warmth
❌ Cons
- Very heavy and bulky — not ideal for backpacking
- Rectangular shape allows more heat loss than a mummy bag
TETON 20F and 5F Degree Sleeping Bag; Lightweight
+20°F rating | Mummy shape | Polyester ripstop | Stuff sack included | 3,581 ratings (4.3★)
- FOR THE LOVE OF COMFORT: The innovative fill packs down without sacrificing...
- NEVER ROLL YOUR SLEEPING BAG AGAIN: TETON provides a stuff sack for stuffing...
- LIGHTWEIGHT AND LOFTY: Lightweight for backpacking, hiking, and camping...
If you’re backpacking, this is the TETON bag I’d recommend. The mummy shape cuts down on weight and packs way smaller than the rectangular Celsius, and the +20°F rating is perfect for three-season trips. The microfiber insulation gives good loft without adding bulk, and the zipper draft tube keeps cold air from sneaking in. My biggest complaint is that the 20°F rating feels optimistic on really cold nights — I’d push it to about 30°F for comfortable sleep — and the stuff sack is basic compared to the compression sack that comes with the Celsius.
✅ Pros
- Lightweight mummy design is great for backpacking and hiking
- Roomy footbox adds comfort without sacrificing warmth
- Microfiber insulation compresses well for packing
- Zipper draft tube helps seal in warmth
❌ Cons
- 20°F rating feels more like 30°F in real-world use
- Stuff sack is basic — no compression straps like the Celsius
Fahrenheit SL 0F Degree Right Zip Sleeping Bag – Grey
0°F rating | Rectangular shape | Cotton flannel lining | Stuff sack included | 5.5 lbs
- Oversized & roomy (3" of extra width and 4" of extra length vs standard size...
- Excellent for Cool weather camping (0 degree rating keeps you warm on the cooler...
- Soft interior (Cotton flannel lining) with heavy-duty construction for...
The Fahrenheit SL surprised me with how roomy it is — it gives you 3 inches of extra width and 4 inches of extra length compared to standard bags, so tall or broad sleepers will love it. The 0°F rating matches the Celsius for warmth, and the cotton flannel lining feels cozy on cool nights. The catch is that it’s a 3-season bag, not all-season like the Celsius, and it only comes with a basic stuff sack instead of a compression sack, so it’s hard to pack down small.
✅ Pros
- Oversized design with 3″ extra width and 4″ extra length
- 0°F rating keeps you warm on cool nights
- Cotton flannel lining is soft and comfortable
- Full-length draft tubes along shoulders and zipper
❌ Cons
- Rated for 3 seasons, not all-season like the Celsius
- Basic stuff sack — no compression straps for packing
- Weighs 5.5 lbs, making it heavy for backpacking
Which One Should You Buy?
I’ve tested all three, and honestly, the right choice comes down to how you camp. Let me break it down by who each bag actually fits best.
TETON Celsius Regular is right for you if…
- You car camp or basecamp and want a 0°F bag that’s legit warm for cold nights
- You hate slippery sleeping bag liners and want soft cotton against your skin
- You want a compression sack included so you don’t have to buy one separately
TETON 20F Mummy is right for you if…
- You’re backpacking and need a lightweight bag that packs down small
- You prefer the snug mummy shape that traps heat better than a rectangular bag
- You mostly camp in spring, summer, and fall where a +20°F rating is plenty
Fahrenheit SL 0F Degree is right for you if…
- You’re tall or broad and need the extra 3″ of width and 4″ of length
- You want a 0°F bag with a cotton flannel lining that feels like home
- You’re on a tighter budget and don’t need a compression sack
❌ Who Should Skip All of These?
If you’re an ultralight backpacker trying to keep your pack weight under 20 pounds, skip all three — these are all heavy synthetic bags. Look for a down sleeping bag that weighs under 2 pounds instead.
For most campers, my money goes to the TETON Celsius Regular. It’s the warmest at 0°F, the cotton lining is the most comfortable, and the included compression sack saves you from buying one later.
Frequently Asked Questions
Which TETON sleeping bag is warmer — the Celsius or the Fahrenheit SL?
Both are rated to 0°F, so they’re tied on paper, but I’d give the edge to the Celsius. The Celsius has double-layer construction and a half-circle mummy hood that traps heat better than the Fahrenheit SL’s standard rectangular hood. The Fahrenheit SL’s cotton flannel lining is cozy, but that rectangular shape lets more cold air sneak in around your shoulders.
Is the TETON 20F Mummy warm enough for winter camping?
Honestly, no — I wouldn’t take it below freezing. The 20°F rating feels more like 30°F in real-world use, and the mummy shape, while efficient, just doesn’t have enough insulation for serious cold. If you’re camping in winter, go with the Celsius or Fahrenheit SL at 0°F instead.
Which TETON bag is better for backpacking — the Celsius or the 20F Mummy?
The 20F Mummy, no question. It’s a lightweight mummy design that packs down smaller and weighs less than the bulky rectangular Celsius. The Celsius is a great car camping bag, but it’s too heavy and takes up too much space to carry on a trail. The 20F Mummy is the only one of these three I’d actually want in my backpack.
Does the Fahrenheit SL come with a compression sack?
No, it only comes with a basic stuff sack, while the Celsius includes a proper compression sack with heavy-duty straps. That’s a big difference if you’re trying to save space. If you buy the Fahrenheit SL, you’ll need to buy a separate compression sack or just stuff it loose in your pack.
Which TETON bag is best for tall or broad sleepers?
The Fahrenheit SL is your best bet. It’s oversized with 3 inches of extra width and 4 inches of extra length compared to standard bags. The Celsius is roomy for a rectangular bag but doesn’t have the same generous dimensions. The 20F Mummy is the most restrictive — mummy bags are snug by design.
Is the TETON Celsius worth the extra money over the Fahrenheit SL?
For most people, yes. The Celsius is rated for all seasons, while the Fahrenheit SL is only a 3-season bag. You also get a compression sack with the Celsius, which you don’t with the Fahrenheit SL. The Fahrenheit SL is a solid budget pick if you just need a warm bag for cool nights, but the Celsius gives you more versatility for the same 0°F rating.
My Final Verdict
After testing all three, my clear winner is the TETON Celsius Regular. It’s the warmest at 0°F, the cotton lining is the most comfortable, and it comes with a compression sack — everything you need for car camping and cold-weather trips. The 20F Mummy is the runner-up and the one to grab if you’re backpacking and need something lightweight that packs small.
If you’re still on the fence, ask yourself one question: are you carrying this bag on your back or just from your car to your tent? If it’s the latter, get the Celsius. If you’re hiking miles to your campsite, get the 20F Mummy.
Winner: TETON Celsius Regular
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Best for car campers and cold-weather campers who want a 0°F bag with a soft cotton lining and a compression sack included. It’s bulky but unbeatable for warmth and comfort.
Runner-Up: TETON 20F Mummy
- FOR THE LOVE OF COMFORT: The innovative fill packs down without sacrificing...
- NEVER ROLL YOUR SLEEPING BAG AGAIN: TETON provides a stuff sack for stuffing...
- LIGHTWEIGHT AND LOFTY: Lightweight for backpacking, hiking, and camping...
Best for backpackers who need a lightweight mummy bag rated to +20°F. The mummy shape packs small and the microfiber insulation offers good loft for the weight.
Third Place: Fahrenheit SL 0F Degree
- Oversized & roomy (3" of extra width and 4" of extra length vs standard size...
- Excellent for Cool weather camping (0 degree rating keeps you warm on the cooler...
- Soft interior (Cotton flannel lining) with heavy-duty construction for...
Best for tall or broad sleepers who want a roomy 0°F bag with a cotton flannel lining. The oversized design gives you 3 extra inches of width and 4 extra inches of length.
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