Review: Outdoor Research Helium II Jacket

Ultralight Rain Jacket
Outdoor Research Helium II Jacket
$159, 6 oz. (men’s medium)
Sizes: men’s XS-XXL, women’s XS-XL

Whether hiking through heavy, cool mist while backpacking the Wonderland Trail in Mount Rainier National Park, pulling this shell on frequently to fend off cold wind and rain showers during a five-day backpacking trip in The Maze District of Canyonlands National Park in early March, or wearing it on local trail runs in mixed weather—including heavily falling, wet snow for over two hours—the featherweight Helium II Jacket demonstrated its value as one of today’s best ultralight, waterproof-breathable rain jackets.

The Outdoor Research Helium II Jacket.
The Outdoor Research Helium II Jacket.

That backpacking trips on the Wonderland Trail and in Canyonlands’ Maze illustrate a major advantage of the Helium: It’s one of the lightest and most packable waterproof, fully seam-taped, and breathable rain jackets out there today. With a forecast was for mostly dry weather, I could forego carrying a heavier and bulkier rain jacket—and mostly carrying it rather than wearing it—knowing the Helium would give me all the protection I needed at about half the weight, bulk, and cost of a high-quality, technical rain shell.

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The Outdoor Research Helium II Jacket.
The Outdoor Research Helium II Jacket.

Constructed from 30-denier ripstop nylon, waterproof-breathable Pertex Shield, it fought off dumping wet snow while I ran and hiked. The jacket employs Diamond Fuse technology, which uses yarns with diamond-shaped filaments that lock together, lending it relatively good durability and snag-resistance for a fabric this light and improving its water-beading properties. Still, this fabric is ultralight: It will stand up to wearing a backpack over it, but likely tear too easily for hiking off-trail in forest or rock climbing.

Breathability is just okay. When hiking uphill on the Wonderland Trail, carrying a full pack, the Helium got a little clammy inside but was tolerable. On autumn trail runs of up to two hours in my local foothills, I could keep the hood up in strong, cold wind without building up much moisture inside—mostly because I wasn’t overheating. In other words, while it doesn’t breathe as well as the best ultralight, non-waterproof wind shells, it performs as well as needed in most hiking and trail-running circumstances in which I’d wear it—and offers the reassurance of waterproof protection.

The jacket feels very comfortable as soon as you put it on, with a close fit that has space to layer midweight insulation under it. The adjustable hood uses a single drawcord in the back and wraps snugly around your head, although the small brim offers negligible face protection.

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The shell stuffs into its one zippered chest pocket—which is large enough for a smartphone—packing down to the size of a large coffee mug (and has a carabiner loop). The waterproof front zipper, like all such zippers, moves a little more slowly than standard zips. The elasticized hem and cuffs, while not adjustable, adequately seal out drafts.

With mediocre breathability and durability and a minimalist hood, the Helium II certainly isn’t as versatile as a fully technical, all-conditions rain shell. (See my picks for “The 5 Best Rain Jackets for Hiking and Backpacking.”) But it is about half the weight and bulk of most high-quality rain shells.

The Outdoor Research Helium Pants ($119, 5.4 oz.), made with the same 30-denier ripstop nylon Pertex Shield, have elasticized waist and cuffs with 12-inch zippers for pulling them over boots, and stuff into the zippered rear pocket.

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The Outdoor Research Helium II Jacket stuffed.
The Outdoor Research Helium II Jacket stuffed.


Weather Protection

The Verdict

For lightweight backpackers, dayhikers, and trail runners who need a just-in-case ultralight shell for wind and rain, the Outdoor Research Helium II Jacket delivers waterproof protection and okay breathability in a compact package that’s a good value for this degree of performance and low weight.



You can support my work on this blog by clicking any of these affiliate links, at no cost to you, to purchase the men’s or women’s Outdoor Research Helium II Jacket at or, the men’s Helium II Jacket at, or the women’s Helium II Jacket at You can purchase the men’s or women’s Outdoor Research Helium Pants at or, or the men’s Helium Pants at, or the women’s Helium Pants at

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See my review of “The Best Ultralight Hiking and Running Jackets” and “The 5 Best Rain Jackets for Hiking and Backpacking,” and all of my reviews of ultralight wind shells, ultralight rain jackets, and outdoor apparel at The Big Outside.

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 of my reviews and my expert buying tips.

—Michael Lanza

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 Wilderness 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 Wilderness Backpacking Trip,” the lightweight backpacking guide, and “How to Know How Hard a Hike Will Be.”

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