Patagonia Nano-Air Ultralight Full-Zip Hoody Review
The Patagonia Nano-Air Ultralight Hoody ($249) is a synthetic jacket that’s fantastic for pushing hard in cool-to-cold conditions—basically any time when breathability matters more than outright warmth. It’s one of the lightest insulated jackets available, and perhaps streamlined to a fault—no hand pockets, no hem or hood adjustments. But despite its minimal build, it's become a favorite of the Better Trail testing team: We've taken this jacket running on the windy coast of Spain, climbing in Patagonia, and on a week-long traverse of New Zealand's Southern Alps. For cold-weather trail running, ski touring, and fast-and-light alpine missions, it delivers a rare blend of comfort, airflow, and packability.
Warmth
Comfort & Mobility
Breathability
Weight & Packability
Weather Resistance
Sustainability
Weight
8.8 oz.
Insulation
20g FullRange
Fabric
30D polyester
Packable
Yes (pocket)
Pros
Cons
Patagonia Nano-Air Ultralight Hoody
For this season's top models, see our guide to the Best Synthetic Insulated Jackets.
The Patagonia Nano-Air Ultralight Full-Zip Hoody is designed to shed heat, not hold onto it, so this isn’t really the category you should judge it by. Designers gave this jacket a thin layer of 20-gram synthetic FullRange insulation throughout the body and hood, paired with highly breathable, uninsulated side panels. As with many active insulators, including the Arc’teryx Atom SL (which contains 40g insulation and fleece sides) and the Patagonia Nano-Air Light Hybrid Hoody (also 40g, with the addition of a full fleece back and underarms), the Nano-Air Ultralight provides just enough insulation to take the edge off cold days without causing you to overheat when you’re working.
Most of my testing consisted of trail runs and fast hikes throughout fall and winter, and I’ve found that this jacket’s (impressively wide) temperature sweet spot falls between the high 20s and low 50s, depending on your level of activity. For hiking in temps at the upper end of that range, the Nano-Air Ultralight is comfortable when worn over a T-shirt or with a long-sleeve base layer into the 40s. Where it really clicks, though, is cold-weather trail running. With the thermometer in the 30s, I often wore it over a short-sleeve base layer; in the high 20s, a lightweight long sleeve was enough. On many winter runs, my setup looked almost comically minimal—shorts, thin glove liners, and the Patagonia Nano-Air Ultralight—but I stayed nicely warm as long as I kept moving.
It's very similar in intent and overall warmth to the Arc'teryx Atom SL, though the Nano-Air Ultralight feels a bit lighter and slightly more breathable. (One notable difference is the hood: The Nano-Air’s is insulated, whereas the Atom SL’s is not.) The Nano-Air Light Hybrid, on the other hand, is a bit more of a toss-up. It contains heavier insulation, but covering the entire back with fleece rather than synthetic fill increases the area where heat is lost. Both Nano-Airs are extremely breathable, with the Hybrid perhaps being slightly less warm.
The Nano-Air Ultralight uses the same soft polyester fabric on the inside and outside, and it feels fantastic on my skin. There’s no crinkly shell, no stiff panels, and no sense of bulk anywhere on my body, which makes sense given that this jacket weighs a paltry 8.8 ounces (it’s actually the lightest synthetic insulated jacket Better Trail has tested thus far).
Mobility is outstanding as well. The Nano-Air has a subtle stretch, but more importantly, it has almost no mass to get in the way. Whether I’m running with poles, scrambling, or reaching overhead, it never restricts my movement. On long runs, it routinely felt like I wasn’t wearing an insulated layer at all—that’s about the highest praise I can give a midlayer that’s designed for movement.
The only comfort drawback is the Nano-Air’s hood. It’s clearly designed to accommodate a helmet, which means there’s extra fabric when worn bareheaded. In windy conditions along the northern coast of Spain, the hood flapped around noticeably. It stays on thanks to an internal elastic system, but it can be distracting. Compared to the Atom SL’s slimmer, more adjustable version, the Nano-Air’s hood design is less refined—it’s not terrible, but as one Better Trail editor noted (pictured below), it’s at its best on top of a helmet.
This is where the Patagonia Nano-Air Ultralight separates itself from just about every other synthetic jacket on the market. Its breathability is as good as it gets, with only the Nano-Air Light Hybrid and the Atom SL in the running as true competitors. The combination of thin, 20-gram insulation and uninsulated side panels allows heat and some moisture to escape, rather than build up as you ski tour, trail run, or do any other activity that gets your blood pumping.
Across dozens of runs and hikes in the fall and winter, I only overheated once—and that was during a run with temperatures in the high 40s, asking a lot of any lofted synthetic jacket, even an active insulation piece. In colder conditions, the Nano-Air Ultralight regulates my body heat beautifully. I’ve never experienced that clammy feeling common with many of its competitors.
Compared directly to the Atom SL, another popular active insulator, the Nano-Air Ultralight breathes slightly better, especially during sustained aerobic output. (This makes sense, given that it’s covered with thinner insulation.) The fleece-backed Nano-Air Light Hybrid may have a slight leg up on it, but those would be my top two choices for preventing yourself from getting swamped out if you’re chugging uphill for hours but still want some protection from the cold. You can read more about our favorite options in the active insulation category here.
At just 8.8 ounces, the Patagonia Nano-Air Ultralight Full-Zip Hoody has a shockingly low weight for a synthetic insulated jacket, a range that’s more commonly inhabited by ultralight down models like the Mountain Hardwear Ghost Whisperer. It’s also highly compressible: Using its own chest pocket, it packs down easily to about the size of a grapefruit.
This is a jacket I never hesitate to bring for cold weather, whether I’m heading out for a long run, stuffing it into a climbing pack, or even clipping it to a harness (that last one is a favorite use from Better Trail’s resident hardcore climber). Compared to the Atom SL, the Nano-Air Ultralight is about 1.1 ounces lighter and compresses slightly smaller; the Nano-Air Light Hybrid weighs 3 ounces more and is bulkier. All of these synthetic insulated jackets are quite packable, but the Ultralight feels more optimized for missions where every gram counts.
Weather protection is limited, which is predictable given the Nano-Air’s design. Its face fabric beads light moisture initially, but it wets out quickly in sustained drizzle. I wouldn’t bring it as my primary layer if rain were in the forecast, though it handled brief mist and passing drizzle without issue.
Wind resistance is better than expected but still secondary to breathability. It’s comfortable in strong winds—up to around 30 to 40 mph—but without hem or hood drawcords, it never fully seals up. In gusty conditions, I often wished for a cinch at the hem and hood to lock things down more securely. The hood stays on, but it moves around more than I’d like. For anything more than intermittent moisture or for outings in exposed terrain, I’d pair the Nano-Air with a breathable shell.
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Patagonia built the Nano-Air Ultralight with the same 30-denier face fabric as the Nano-Air Light Hybrid. It’s a great material for keeping weight down while adding a decent amount of longevity. (The Atom SL’s face fabric is thinner, at 20D, but it’s nylon, which is a bit stronger.) After about five months and roughly 20 wears, my jacket still looks new.
Its face fabric has held up well to trail running, hiking, chopping wood, and general use. The zippers run smoothly, the stitching is clean, and nothing feels fragile despite the jacket’s minimal weight. Our other Better Trail tester adds that, aside from one catastrophic tear during a chimney climb—an environment that would destroy almost any lightweight jacket—her sample has survived a year and a half of hard climbing and running. The lightweight insulation’s loft will likely degrade before the shell fails.
In keeping with the Nano-Air’s minimalist design, its features are sparse. You get one zippered chest pocket that can fit a phone and a helmet-compatible, non-adjustable hood, but that’s it. If you want hand pockets, the Arc'teryx Atom SL or the Nano-Air Light Hybrid are better bets—but neither of those has a chest pocket.
The hood works best when you throw it over a helmet, reinforcing the Nano-Air’s alpine and endurance focus. For runners and climbers, the lack of features is part of the appeal. For anyone wanting a more well-rounded daily jacket, though, it can feel limiting.
Tester size: 6’2”, 175 lb.; 41" chest, 31" waist
Size tested: Men’s large
The Patagonia Nano-Air Ultralight’s fit is mostly regular with perhaps a slightly trim bias, and slightly boxier than the Atom SL. I’m fairly tall and thin, and I found the shoulder and arm length to be perfect. This jacket layers easily under a shell without bunching. My fellow Better Trail tester deemed it good for throwing on over a thin long-sleeve base layer or a T-shirt, but not much more.
Arc’teryx Atom SL Hoody ($280): Increase Warmth and Versatility
These two active midlayers are designed for the same purpose: keeping your temperature in check while you go hard in cold weather. The Atom SL is also very good at that, but it will cause your furnace to run a bit hotter than the Nano-Air Ultralight. It’s filled with 40-gram synthetic insulation that’s heavier than the Nano-Air’s 20-gram fill, and it’s warmer as a result. The Atom SL is also a bit more user-friendly, with two hand pockets and an adjustable hood. Overall, it’s a more versatile jacket that you can wear for some other activities that don’t involve trying to set FKTs. But if low weight and maximum breathability are still what you’re after, the Nano-Air is still the correct choice. For more, read our review of the Atom SL Hoody.
Patagonia Nano-Air Light Hybrid Hoody ($299): Another Breathability Champ
As you can infer from their names, the Nano-Air Light Hybrid Hoody is aimed at the same user base as its Ultralight Full-Zip cousin. Choosing between the two is splitting hairs when it comes to warmth and airflow, but they do feature different designs. The Hybrid is constructed with 40-gram FullRange insulation that’s heavier than what’s in the Ultralight, but it mitigates that with a back and underarm section that’s constructed with Patagonia’s super-breathable R1 Air fleece. As a result, the Hybrid offers even better temperature regulation—if just slightly—as well as two hand pockets rather than a chest pocket. It’s also a bit heavier (11.8 oz.) and less packable, but it remains our top pick for high-octane cold-weather adventures. The only catch? It’s $50 more, which is a fair chunk of change. For more, read our Nano-Air Light Hybrid Hoody review.
The Nano-Air Ultralight excels in high-output efforts in cool-to-cold conditions, where breathability and mobility take priority over outright warmth. It’s one of the lightest and most packable insulated jackets on the market, and that minimalist build comes with a pared-down feature set—no hand pockets or adjustments.
Warmth
Comfort & Mobility
Breathability
Weight & Packability
Weather Resistance
Sustainability
Stretchy, breathable, light, and packable, the Atom SL is built for moving fast in cool temps. It also blocks wind surprisingly well; however, its lack of warmth makes it a fairly specialized active piece.
Warmth
Comfort & Mobility
Breathability
Weight & Packability
Weather Resistance
Sustainability
Active insulation at its finest, the Patagonia Nano-Air Light Hybrid Hoody combines 40-gram synthetic fill with fleece panels for a breathable, mobile, and comfortable jacket that’s built to move with you. However, it falls short in both warmth and weather resistance compared to much of the competition.
Warmth
Comfort & Mobility
Breathability
Weight & Packability
Weather Resistance
Sustainability
Is the Nano-Air Ultralight for You?
The Patagonia Nano-Air Ultralight Full-Zip Hoody makes a ton of sense for people who move fast, pack light, and value breathability over warmth for their winter adventures. If you spend your time trail running, ski touring, climbing, or otherwise covering lots of ground in cool conditions, it’s one of the best active insulation layers available. This is not a casual jacket, but for high-output use where every gram matters, the Nano-Air stands out.
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