Head-to-head · Best 0 Degree Sleeping Bags

Sea to Summit Spark 0F vs Western Mountaineering Kodiak MF

Which is the better buy? Side-by-side on rating, price, strengths, and watch-outs — with the published ratings we averaged to get there.

The short answer

Western Mountaineering Kodiak MF comes out ahead by a narrow margin (4.4 vs 4.6). The gap is mostly about Cold-weather campers and side sleepers who want the most reliable 0°F warmth and room to move, and don't mind paying a premium. — read the strengths below before deciding.

Ranked #4 in Best 0 Degree Sleeping Bags

Sea to Summit Spark 0F

4.4

$349as of Jun 8

The Spark 0F is the ultralight of this group, packing a genuine 0°F-rated bag into about 2 lb 7 oz and a sub-10-liter stuff size. It uses 850+ fill Ultra-Dry down and reviewers find its temperature rating accurate. The trade-offs are a snug, less-forgiving cut and a thin shell that offers little wet-weather protection, plus a steep price for the warmth.

Strengths

— Among the lightest 0°F down bags at roughly 2 lb 7 oz
— Sub-10-liter packed size, the most compressible bag here
— 850+ fill power Ultra-Dry treated goose down resists moisture

Watch-outs

— Snug ultralight cut is less forgiving than the Kodiak or Ibis
— Thin shell offers little wet-weather protection
— Pricey at roughly $649-$679 for the warmth delivered

$349 · Buy at seatosummit.com Full review →

Higher ratedRanked #1 in Best 0 Degree Sleeping Bags

Western Mountaineering Kodiak MF

4.6

$895as of Jun 7

The Kodiak MF is the warmest 0°F bag most reviewers have ever tested, exceeding its rating with a roomy, side-sleeper-friendly cut. OutdoorGearLab consistently names it their top winter pick and found it performed more like a -20°F bag than a 0°F one. The trade-off is a list price near $900 and a wide cut that costs some warmth-to-weight efficiency versus narrower mummies.

Strengths

— Tested warmer than its 0°F rating; held testers to roughly -10°F with light layering
— 1.88 lb of 850+ fill goose down with continuous baffles you can shift top-to-bottom
— Wide-cut mummy with generous shoulder, hip and footbox room for side sleepers

Watch-outs

— List price near $895-$950 is among the highest in the category
— Wide cut adds dead air space, so it is not the most weight-efficient 0°F option
— Continuous baffles can shift down underneath you if not redistributed

$895 · Check Price on Amazon Full review →

How they stack up

Sea to Summit Spark 0F

The lightest and most compressible bag here, undercutting the Therm-a-Rest Parsec 0F on weight and packed size and far lighter than the Western Mountaineering Kodiak MF, Feathered Friends Ibis ES 0 and Mountain Hardwear Phantom 0, but with a snugger cut and a thin, less weatherproof shell.

Western Mountaineering Kodiak MF

The roomiest and warmest bag here, beating the Mountain Hardwear Phantom 0 and Therm-a-Rest Parsec 0F on real-world warmth and the Feathered Friends Ibis ES 0 on cut width, but it is heavier and pricier than the lighter Sea to Summit Spark 0F.

Specs side-by-side

Spec	Sea to Summit Spark 0F	Western Mountaineering Kodiak MF
Temperature Rating	0°F limit / 14°F comfort	0°F (-18°C)
Fill Power	850+ Ultra-Dry goose down	850+ goose down
Fill Weight	29.6 oz (840 g)	1.88 lb (30 oz)
Total Weight	2 lb 7 oz (1113 g)	2 lb 12 oz
Packed Size	9.9 L	9 x 18 in
Shell	Ultralight nylon	20D MicroLite XP nylon
Zipper	Full-length YKK with draft tube	—
Cut	Snug ultralight mummy	Wide mummy, continuous baffles
Warranty	—	Lifetime craftsmanship

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