Built to be the only bag you need from -20°F to 40°F, the NEMO Sonic -20 sleeping bag is warmer and more fine-tuneable than ever before. Time to start planning some big-mountain adventures.
Fill
800-fill-power down
Temperature Rating (F)
-20 degrees (F)
- Updated Thermo-Gills™ feature a multi-stage zipper system that increases the bag's usable temperature range and allows you to fine-tune your comfort while inside it
- Chevron baffle construction better compartmentalizes down, eliminating migration and keeping the down evenly lofted
- Upgrades include a redesigned profile and draft collar, plus bolstered draft tubes; offset zipper creates a thermally efficient seal
- Shell and liner fabrics are fully recycled to the Global Recycled Standard (GRS)
- Shell and liner materials are bluesign® approved
- 800-fill-power, PFC-free hydrophobic down retains warmth in extra-cold conditions
- Down is certified to the Responsible Down Standard (RDS)
- Toester™ footbox keeps feet warmer, provides a waterproof barrier against tent wall condensation and protects down from moisture while drying damp clothes inside the footbox
- Stretch construction at the knees allows for comfortable side sleeping
- Covered by the NEMO Lifetime Warranty
Imported.
Temperature ratings are intended as a guideline to help you compare products, rather than a guarantee of warmth, since many different factors contribute to your comfort while you sleep. Backpacking bags are typically rated for temperature according to an independent testing protocol—currently International Organization for Standardization (ISO) 23537, though some older items followed European Norm (EN) 13537. Testing is based on a person wearing one base layer and a pair of socks, sleeping on an insulated surface with a minimum R-value of 5.38.
Each bag then gets 2 ratings: the Comfort rating is the lowest temperature at which the bag will keep the average "cold sleeper" comfortable, and the Lower Limit rating is the lowest temperature at which the bag will keep the average "warm sleeper" comfortable. Some brands determine their own temperature rating by aligning to the Comfort rating for women’s bags, to the Lower Limit rating for men’s bags, or somewhere in the middle for nongendered bags.
View all NEMO Backpacking Sleeping BagsEach bag then gets 2 ratings: the Comfort rating is the lowest temperature at which the bag will keep the average "cold sleeper" comfortable, and the Lower Limit rating is the lowest temperature at which the bag will keep the average "warm sleeper" comfortable. Some brands determine their own temperature rating by aligning to the Comfort rating for women’s bags, to the Lower Limit rating for men’s bags, or somewhere in the middle for nongendered bags.
| Best Use | Backpacking Mountaineering |
|---|---|
| Tested Lower Limit | -20 degrees (F) - ISO |
| Tested Comfort | Unavailable |
| Temperature Rating (F) | -20 degrees (F) |
| Temperature Rating (C) | -29 degrees (C) |
| Shell | Recycled nylon |
| Zipper Location | Left |
| Insulation Type | Down |
| Water-Resistant Down | Yes |
| Fill | 800-fill-power down |
| Lining | Recycled polyester |
| Sleeping Bag Shape | Mummy |
| Shoulder Girth (in.) | 63 inches |
| Hip Girth (in.) | 58 inches |
| Gender | Unisex |
| Sustainability | Product meets the bluesign® criteria |