Our Verdict
Our Analysis and Test Results
You don't want to sacrifice warmth, even when every ounce counts — that's the design philosophy behind the Feathered Friends Hummingbird UL 30. But it's very slim, mummy-style cut leaves little room to spare and may be downright too restrictive for some.
Warmth
The Hummingbird UL contains 11.5 ounces of ultra-premium, 950+ fill-power, responsible goose down. Although this is a little less insulated than other primo bags with similar temperature ratings, it has a narrower fit, so it requires less fill to provide the same amount of warmth. In addition, the snug fit means there's less empty space for your body heat to escape, so you feel warmer.
What's more, the draft tube that runs the full length of the zipper is wonderfully plush, helping keep out the cool night air. The collar, too, is plenty lofty — it and the hood can be cinched down very tight with a single drawcord to totally lock in your heat on super-cold nights.
Feathered Friends does not put their sleeping bags through the formal EN temperature testing. Instead, they supply their own manufacturer rating of 30°F for the Hummingbird. We felt it provided similar warmth to the average bag with an EN lower limit rating of 20°F. With this level of insulation, it's an excellent middle-of-the-road bag that's well-suited for summer, and usable in the shoulder seasons (if you layer well).
Weight
Weighing in at a measly 1.3 pounds in size Regular, the Hummingbird UL is truly ultralight. This is made all the more impressive by its robust zipper system, plush hood, and impressive warmth — all of which add to the weight but somehow don't tip the scale too far.
On paper, a few bags with reported weights and temperature ratings seem to offer even better warmth-to-weight ratios than the Hummingbird. Our testers, however, found many of the temperature ratings on these competing bags to be overly optimistic. The Hummingbird's insulation, in contrast, felt much warmer than its 30°F rating would suggest – we struggle to attribute its outstanding performance to anything other than sorcery.
Comfort
While the Hummingbird UL is made of cloud-like fluff contained within lofty baffles that feel like whipped butter to the touch, your comfort is a bit more up in the air. Part of its no-excess design is a trim, mummy-style bag with little room to spare. As a 170-pound, 5'10" man, our lead tester reported that he didn't find the Hummingbird to be all that restrictive for an ultralight bag.
With a shoulder girth of 58 inches, the Hummingbird UL is objectively one of the narrowest bags we tested. Virtually all of our testers are happy with bags 64 inches wide, but as the girth shrinks, complaints steadily increase. Other testers, particularly side sleepers and those with broad shoulders, found the Hummingbird to be constrictive.
A minor complaint some of our testers had with the Hummingbird UL is the nosiness of its Pertex Endurance shell fabric, which has a distinct crinkling sound. Although it's only subtly louder than most other bags, some lighter sleepers felt the difference was enough to disturb their sleep.
Packed Size
The top-tier 950+ fill-power goose down compresses like no other, allowing the Hummingbird UL to pack down to a very small size. We measured 5.5 liters – that's smaller than the storage capacity on many backpack lids. Plus, it weighs only 1.3 pounds, so you can store it virtually anywhere it'll fit without throwing your pack out of balance.
Even though it comes with a “stuff sack”, to fully enjoy the small packed size of the Hummingbird UL, you will need to buy a third-party compression sack. But with the standard stuff sack, the bag's loft lets it squish and mold as needed inside your pack – you could always shove it under everything else or beside something large, like a bear can.
Features
Although it may come off as just a simple mummy bag, we like the Hummingbird UL's design. The #5 YKK two-way separating zipper with locking sliders extends from the shoulder to the toe box and features an effective anti-snag zipper slide. The fabric adjacent to this zipper is stiffened by an internal strip of flexible plastic that further reduces the likelihood that the fabric will get caught in the zipper's teeth. It's a fantastic combo that produces one of the smoothest zipper slides we've ever had the pleasure of using.
This long zipper allows the Hummingbird UL to vent excess heat, expanding the range of temperatures at which it can be used comfortably. Our testers could open the lower slider to let our feet breathe while keeping the rest of the bag draft-free. When fully opened, the long zipper also turns the bag into a quilt for sharing on a chilly morning or between climbing partners during a “light and fast” bivouac.
We really like the hood design on this bag. There's a single drawcord that can tighten both the hood and the collar. This cord is thin, so when drawn taut, it could put uncomfortable pressure on your neck or chin, but it's positioned so you can easily protect yourself with the abundant loft of the collar and hood. While we only use the closure flap at the top of a sleeping bag's zipper on the coldest nights, the snap on this flap held firmly but also detached quickly enough for middle-of-the-night bathroom trips.
Should You Buy The Feathered Friends Hummingbird UL 30?
The Hummingbird UL 30 is a comfortable ultralight bag, but we wouldn't recommend it for anyone larger than our lead tester (5'10", 170 lbs). There is a long version option for taller individuals, but no width options are currently available. Smaller backpackers will reap the rewards of its specialty design. It's an excellent sleeping bag to cut ounces off the base weight of your backpacking kit.
What Other Backpacking Sleeping Bags Should You Consider?
If you want a little more space to stretch out and roll around, check out the Western Mountaineering MegaLite. In many ways, it's very similar to the Hummingbird UL 30, but it's warmer and has 6 more inches of shoulder space and 4 more inches of hip space. If these two bags are outside your budget, consider the Exped Terra 15. It's a warmer, more comfortable bag that will be a bit heavier in your backpack, but much lighter on your wallet.
| Awards | The Best Ultralight Option |
|---|---|
| Price | $549 List Check Price at Feathered Friends |
Overall Score ![]() |
|
| Star Rating | |
| Bottom Line | This premium down bag is exceptionally warm for its weight, though its narrow cut best fits smaller backpackers |
| Pros | Ultralight, premium materials, anti-snag zipper |
| Cons | Expensive, narrow mummy fit |
| Rating Categories | Feathered Friends Hu... |
| Warmth (25%) | |
| Weight (25%) | |
| Comfort (20%) | |
| Packed Size (15%) | |
| Features (15%) | |
| Specifications | Feathered Friends Hu... |
| Temperature Lower Limit Rating | 30°F (manufacturer rated) |
| Comfort Rating | Not Available |
| Insulation | Goose down, RDS-certified |
| Packed Volume | 5.5 L |
| Measured Weight (Size Regular) | 1.3 lbs |
| Fill Power | 950+ FP |
| Listed Fill Weight | 11.5 oz |
| Shell Material | 10D Pertex Endurance UL |
| Liner Material | Flite 15D ripstop nylon |
| Hydrophobic Down | No |
| Neck Baffle | No |
| Small Organization Pocket | No |
| DWR Treatment | No |
| Zipper Info | Full-length / left |
| Listed Shoulder Girth | 58 in |
| Listed Hip Girth | 52 in |
| Listed Foot Girth | 38 in |
| Compression or Stuff Sack Included? | Stuff sack |
| Measured Compression/Stuff Sack Weight | 0.6 oz |










