All-Season Shell Jacket
Outdoor Research Helium AscentShell Jacket
$399, 11.5 oz. (men’s medium)
Sizes: men’s S-XXL, women’s XS-XL
moosejaw.com
Heading to Iceland for a couple weeks of hiking—including trekking hut to hut, when we’d be committed to hitting the trail every day, no matter the weather in a place where it’s rarely good—I knew I’d basically be living in my rain shell, so I wanted it to feel good and to work. I wore OR’s Helium AscentShell Jacket for several hours every day for a week trekking Iceland’s Laugavegur Trail and Fimmvörðuháls Trail, through cool temps with wind and rain on most days, and on several dayhikes along Iceland’s Ring Road, with similar weather, including hard, wind-driven rain at times. And this lightweight shell rose to the challenge of some of the most difficult conditions that most hikers, backpackers, and climbers ever face.

Besides seven days of hiking on that hut trek, I wore the Helium AscentShell Jacket on dayhikes of the peaks Blahnukur and Brennisteinsalda in Iceland’s Fjallabak Nature Preserve, Súlur near the town of Akureyri in Iceland’s north, a 10-mile dayhike in Vatnajokull National Park, and a half-day hike to Glymur Falls. All of those outings featured wind and cool to cold temps, usually accompanied by on-and-off rain ranging from light and heavy mist to steady rainfall. I also wore it hiking in strong, chilly wind and rain showers in Idaho’s City of Rocks National Reserve and Castle Rocks State Park in June.
The lightweight, fully seam-taped Helium AscentShell Jacket employs a unique combination of very durable Pertex Diamond Fuse fabric laminated to OR’s proprietary three-layer,electrospun, waterproof-breathable AscentShell membrane with 30-denier nylon ripstop and a 7-denier tricot backer. I stayed completely dry through days of hiking in rain, thanks also to the AscentShell membrane’s very good breathability, which prevented me from overheating. I’ve found seen that same high breathability in several other OR jackets that use that membrane.
That’s excellent performance for a shell weighing under 12 ounces (men’s medium). Although my hikes lacked circumstances that would truly test the jacket’s durability, I’ve found Pertex Diamond Fuse fabric to be quite tough in other shells that feature it.
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That superior breathability also translates to it not being fully windproof: I could feel a slight amount of wind coming through the jacket on extremely windy days. That might become an obstacle to comfort only in the most extreme wind and cold temps, for which you can usually add appropriate insulation layers, anyway. In the range of conditions that most hikers, backpackers, and climbers encounter, the breathability is welcome when you’re on the move and the very slight wind penetration even feels good.
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I fitted the adjustable and helmet-compatible hood—using a one-hand pull in the back and front drawcords positioned inside the collar—once and never had to readjust it. The hood flips up easily and remains unobtrusive when downand its flexible wire brim kept rain off my face even when hiking into heavy, wind-driven, cold mist.
The supple feel and fit of the Helium AscentShell Jacket allows for layering underneath without the shell crossing the line to excessively bulky. The sleeves have hook-and-loop cuffs and enough length and mobility in the underarm panels to never ride up, even when reaching overhead. The jacket’s adjustable hem extends well below the waist, helping to keep the top of my pants dry and never riding up under a pack hipbelt when I bent forward.
The three zippered external pockets include one on the chest that’s slightly larger than a smartphone and two large hand pockets, positioned above a pack or harness belt, that each could easily swallow a pair of gloves. Inside, two mesh stuff pockets are ideal for drying gloves or even climbing skins and a zippered internal chest pocket has an earbuds port.
While the Helium AscentShell Jacket lacks pit zips, I didn’t miss them because of its superior breathability—and I sweat a fair bit. But people who sweat prodigiously may prefer a shell with underarm zippers.
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Outdoor Research Helium AscentShell Jacket
The Verdict
The Outdoor Research Helium AscentShell Jacket is one of the lightest and most protective, breathable, and durable high-performance, all-conditions shells on the market for hikers, backpackers, climbers and other users.
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You can support my work on this blog, at no cost to you, by clicking any of these affiliate links to purchase a men’s or women’s Outdoor Research Helium AscentShell Jacket at moosejaw.com or outdoorresearch.com.
Want a rain shell with the same waterproof-breathable AscentShell membrane but $150 cheaper? See my review of OR’s Microgravity AscentShell Jacket.
See also “The 5 Best Rain Jackets for Hiking and Backpacking,” “5 Pro Tips For Buying the Right Rain Jacket For the Backcountry,” and all of my reviews of rain jackets and outdoor apparel and that I like.
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Whether you’re a beginner or seasoned backpacker, you’ll learn new tricks for making all of your trips go better in my “12 Expert Tips for Planning a Backpacking Trip,” “A Practical Guide to Lightweight and Ultralight Backpacking,” and “How to Know How Hard a Hike Will Be.” With a paid subscription to The Big Outside, you can read all of those three stories for free; if you don’t have a subscription, you can download the e-guide versions of “12 Expert Tips for Planning a Backpacking Trip,” the lightweight and ultralight backpacking guide, and “How to Know How Hard a Hike Will Be.”
NOTE: I tested gear for Backpacker magazine for 20 years. At The Big Outside, I review only what I consider the best outdoor gear and apparel. See my Gear Reviews page at The Big Outside for categorized menus of all reviews and expert buying tips.
—Michael Lanza