Marmot CWM Sleeping Bag: -40 Degree Down

We’ve read the reviews across the web for the Marmot CWM Sleeping Bag: -40 Degree Down and summarize the results below:

Universal Ranking

PeakScore: N/A (out of 100)
User Rating: 4.6 stars 
Expert Rating: N/A stars

Number of Ratings Reviewed: 51

Pros & Cons

Reasons to buy:

User Reviews

  • Waterproof capabilities to keep you dry.
  • Ample foot space to move around.
  • The construction prevents condensation from entering the bag.
  • Keeps you warm throughout the night in cold conditions.
  • The liner feature sits above your shoulders to keep the warm air inside.
  • Great baffling to distribute the warmth.

Expert Reviews

  • Filled with 900-fill goose down for ample warmth.
  • The 9-baffle section on the chest prevents clumping.
  • The baffles provide ample strength and durability.
  • The hood chamber has 6-baffles to provide heat.
  • The foot-box is reinforced to withstand abuse and prevent holes.
  • The zipper guards prevent snagging.
  • Stays warm even after damp from condensation.
  • The cross-baffle construction provides some stretch for movement.

Reasons NOT to buy:

User Reviews

  • Too warm for slightly-cold/moderate temperatures.
  • Lofty and difficult to fit into a stuff sack.


The Marmot CWM Sleeping Bag: -40 Degree Down is an extremely warm, durable, and waterproof option that is well-suited for those who will be sleeping in absolutely brutal conditions. The bag is well designed for ample foot space, prevention of condensation, and distributed baffling. While this bag is too warm for moderate temperatures, it is a personal oven for Himalayan-type weather conditions.


Note: User and expert rankings were reviewed across the web. Some expert reviews include these: 1, 2, 3.