The Feathered Friends Hummingbird UL 20 is among the lightest 20°F down sleeping bags on the market, starting at 1 lb 4 oz. It uses 950+ fill power goose down (some of the highest fill power commonly available) paired with a Pertex® Quantum Pro shell and Pertex® Diamond Fuse in the footbox to maximize warmth-to-weight. For 20°F protection at minimum weight, narrow-cut mummy bags like the Hummingbird outperform wider bags by 4–8 ounces.

For those looking for the absolute lightest 20ºF sleeping bag we make, the Tanager CFL is the champ.

Our UL series of sleeping bags got a massive update for 2026 making them the lightest version yet! We brought in Pertex® Quantum Pro for the shell fabric. It's water-resistant, made without intentionally-added PFAS, is quieter than its predecessor, and lighter overall! We also added Pertex® Diamond Fuse fabric in the interior footbox for added abrasion resistance.

The UL (Ultralight) Series is Feathered Friends' premium line, built with 950+ fill power goose down and Pertex® Quantum Pro shell fabric: the lightest, warmest, most water-resistant materials available. The YF (YFuse) Series uses 900+ fill power goose or Muscovy down and a buttery-smooth Pertex® YFuse® 20D shell, delivering exceptional quality at a lower price point. UL is the choice for absolute minimum weight; YF is the choice for premium quality at $40–$70 less per bag.

Choose a sleeping bag rated approximately 10°F below the coldest temperature you expect to encounter. So if your low for the trip is 30°F, a 20°F bag is the right call. Cold sleepers and women generally benefit from going 5–10°F warmer than the standard recommendation. Warm sleepers can match the expected low without going lower.

Fill power measures how much loft (volume) one ounce of down produces; the higher the number, the more air the down traps and the warmer the bag is per ounce of fill. 950+ fill power goose down is among the highest commercially available; most "premium" outdoor brands top out at 800–850 fill. Higher fill power means a bag can be lighter and more compressible while delivering the same warmth.

Yes. Every Feathered Friends sleeping bag is designed, cut, sewn, filled, and inspected by hand in Seattle, Washington. We have been manufacturing in Seattle since 1972, and we use only RDS (Responsible Down Standard) certified down, sourced ethically without live-plucking or force-feeding. This stands apart from most outdoor brands, which manufacture overseas to lower costs.

Yes! Most Feathered Friends sleeping bags are designed to zip together for couples or shared shelters. You'll need one bag with a left-zip and one with a right-zip; the standardized #5 YKK zippers allow different models to pair, though there will be some length differences. For a purpose-built two-person option, the Spoonbill UL is the dedicated couples' bag in the line.

You can wash a down sleeping bag at home in a front-loading machine using a down-specific cleaner like Nikwax Down Wash or Granger's Down Wash; never use regular detergent, which strips the natural oils that keep down lofted. Tumble dry on low with three or four clean tennis balls to break up clumps as the down dries. Expect 3–4 hours of dry time. Most importantly, never store a down sleeping bag compressed in its stuff sack long-term; store it loose in the breathable cotton storage sack that ships with the bag. For full instructions, check out our Wash & Care information.

Our ultralight down sleeping bags are engineered for any human-powered adventure where shaving ounces and saving pack space are critical, without compromising on thermal efficiency. Built with premium 950+ fill power goose down and featherweight Pertex® shell fabrics, these bags are ideal for:

• Long-Distance Thru-Hikes: Minimizing your base weight is essential for sustained high-mileage days and preserving your joints over a multi-month journey. Our ultralight bags are industry favorites for the "Triple Crown" trails: the Pacific Crest Trail (PCT), Continental Divide Trail (CDT), and Appalachian Trail (AT).

• High-Alpine Routes: For iconic, high-elevation treks like the John Muir Trail (JMT), nighttime temperatures can dip below freezing even in the peak of summer. These bags provide bolstered warmth at a thru-hiker-friendly weight.

• Fast-and-Light Traverses: When moving quickly through demanding terrain, such as Washington's Enchantments zone, keeping your pack compact and light is vital for both speed and safety on the trail.

• General Backpacking & Bikepacking: You don't need to be on a 2,000-mile expedition to benefit from shedding weight. Weekend backpackers and bikepackers appreciate the massive reduction in bulk and weight, leaving more room in their packs or panniers for extra food, technical gear, or simple trail comforts.