By Michael Lanza
You’re out on an all-day hike in the mountains, or a long climb or trail run, or backpacking. The weather forecast looked pretty good before you set out—but no one shared that memo with the wind that just started hammering your summit ridge, or the spitting rain and hail now pelting you as you contemplate the sudden drop in temperature and the miles between you and shelter. The question now is: What’s in your pack?
If you’re smart, it’s an ultralight jacket that takes up little space, but is about to gift you with just the right amount of weather protection when you need it. Here’s how to choose the best ultralight shell for your needs, followed by my freshly updated picks for the best models on the market today, based on real-life field testing and my 25 years of experience reviewing outdoor gear and apparel.
Ultralight Jackets Explained
What is an ultralight shell jacket? There’s no consensus definition, and considerable variation among today’s models. But basically, the term “ultralight jacket” explains their primary advantage: They weigh under 10 ounces (and some less than half that) and are very packable, often stuffing down to the size of a fist—in other words, they can be half or less the weight and bulk of a standard waterproof-breathable jacket. While a few may be partly or even fully waterproof, many are water-resistant and windproof, providing a minimum level of protection from the elements.
While these jackets, also known as ultralight wind shells, are marketed primarily to trail runners, they are often a better choice than a heavier, bulkier rain jacket for dayhikers, climbers, and lightweight/ultralight backpackers who don’t expect to encounter heavy rain. I’ve used many of the models reviewed here for lightweight dayhikes, climbing, and even backpacking when the forecast threatened no more than passing showers or thunderstorms.
Although they certainly look very minimalist, they deliver all the protection you need from wind and light rain—the conditions many of us often encounter, far more often than full-on storms. Some of them are partly or fully waterproof-breathable, and kept me dry in steady rain; but they lack the hood coverage, features, and degree of waterproofing that a heavier rain jacket provides, and I don’t recommend ultralight jackets for hours or days of sustained downpour.
The truth is, because standard, heavier, waterproof-breathable shells are, by definition, not as breathable as shells that are simply water-resistant, they are not the best choice for activities where you sweat a lot, like running or rigorous uphill hiking with a pack on, because they often cause you to get soaked from perspiration. Waterproof-breathable shells have their place, for sure. (See my top picks for the best rain jackets for hiking, backpacking, and climbing.) But they are heavier, bulkier, and more expensive than an ultralight jacket, in addition to being generally less useful in the situations we commonly encounter in the backcountry.
The notion seems counterintuitive, but it’s possible to have too much of a jacket. If you rarely pull on a rain jacket because it’s too much for most circumstances, then you need an ultralight jacket.
Whether you’re a dayhiker, backpacker, climber, ultra-hiker or runner, when you choose the right ultralight shell for your activity and climate, it will probably become the jacket you grab and actually wear most often—and possibly the most versatile piece of outerwear you own, useful in a layering system tailored to any season and multiple outdoor sports.
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How to Choose an Ultralight Jacket
While many ultralight shells are similar in appearance and weight, they can vary significantly in functionality. Simply put, the best ultralight jackets for trail running may be different from the best models for cool-weather hiking or ultralight backpacking, and your choice will also depend on the typical weather you encounter. Here’s what to look for:
• Breathability vs. weather resistance. Ultralight jackets generally trade off fully waterproof protection for better breathability. However, models in this category can vary greatly in how each balances breathability and wind protection, and a few have partially or completely waterproof fabrics while remaining ultralight and packable. But “waterproof” in an ultralight jacket doesn’t generally equal the protection of a two-layer or three-layer, heavier waterproof-breathable jacket (like Gore-Tex); hours of hard rain can cause it to wet through.
• Hybrid vs. uniform shell. “Hybrid” in this context refers to the shell blending some fully waterproof-breathable fabric—usually in the shoulders, torso, and hood—with more breathable, non-waterproof fabric in the sides and underarms, allowing the jacket to release body heat and moisture in areas not likely to receive much direct precipitation. These jackets are versatile for a wide range of conditions and activity levels. By “uniform” shell, I mean either a water-resistant soft-shell fabric or a waterproof-breathable fabric—but one or the other, not a hybrid combination of both.
• Insulated or not. While it’s not usually the case, ultralight jackets occasionally feature a light amount of strategically placed insulation—typically in the torso—making them more of a cool-weather, shoulder-season garment, but also versatile for everything from climbing bigger mountains in summer to aerobic activities like running, Nordic skiing, or even hiking and snowshoeing in winter.
• Hood or no hood. For the most part, I find a simple, uninsulated shell hood almost essential in an ultralight jacket—it provides a noticeable boost in warmth and weather protection at very little cost in terms of weight, bulk, or dollars. Many ultralight shells, but not all, have a hood, and this comes down to personal preference as well as typical usage: If you need a shell simply for local runs of an hour or two in wind or cool temps, with a chance of a light shower, you may not need a hood. If you’re heading into the mountains for hours or days, you probably want a hood.
The Best Ultralight Jackets
I’ve listed the following jackets roughly in order of most breathable and lightest—with the least wind and weather protection and warmth—to most weather-resistant and warmest. But it’s a somewhat subjective order because I’ve chosen to rank shells that are partly or entirely waterproof as having more weather protection than non-waterproof shells that are warmer. For instance, the positions on this list of the Outdoor Research Helium Hybrid Hooded Jacket and Arc’teryx Atom SL Hoody could be interchangeable.
My advice: Look at each of the reviews below to narrow your choices to the two or three that sound best for your needs, and then go to the complete reviews of those jackets to help you make your pick. You will support my work on this blog by purchasing any of these jackets through the links provided here or in the complete reviews. Thanks for doing that.
I encourage you to share your thoughts and experiences with any of these jackets, or another ultralight shell that you like, in the comments section at the bottom of this story.
From a chilly and very windy October dayhike of 11,749-foot Mount Timpanogos in Utah’s Wasatch Range, to numerous fall and winter trail runs and rides, in cool temps and conditions all over the meteorological map, Smartwool’s PhD Ultra Light Sport Jacket distinguished itself for its breathability. The key to that is a blend of Merino wool and stretchy polyester mesh under the arms and between the shoulder blades, which creates good ventilation without exposing you to much wind or precipitation. When I sweated hard on trail runs in temps in the 40s and 50s, the jacket protected me from cold wind and breathed well enough that it never got more than slightly damp on the inside when my base layer was quite wet.
The jacket also features Smartwool’s thinner-than-a-wafer PhD Ultra Light nylon shell fabric through most of the torso and sleeves, with small vent holes (covered to keep rain out) at the front of the shoulders. A DWR (durable, water-repellant treatment) on the fabric fends off light rain, although it wets through in a steady rain. The high breathability also means limited wind and weather protection, making it better for short, aerobic outings that, say, an all-day hike in the mountains.
See my complete review of the Smartwool Men’s PhD Ultra Light Sport Jacket and the hooded Smartwool Women’s PhD Ultra Light Sport Jacket.
BUY IT NOW You can support my work on this blog by clicking any of these links to purchase a Smartwool Men’s PhD Ultra Light Sport Jacket at moosejaw.com, or a Smartwool Women’s PhD Ultra Light Sport Jacket at moosejaw.com, or the women’s anorak version at rei.com.
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Black Diamond Alpine Start Hoody
$149, 7.5 oz. (men’s medium)
The range of uses to which I’ve put my Alpine Start Hoody speaks volumes about its versatility. I’ve worn it in strong wind, light rain, and cool temps on a 17-mile dayhike through New Hampshire’s Northern Presidential Range; on a 25-mile dayhike in light rain in the Grand Canyon; trail running in the hills of central Massachusetts and standing on the blustery summit of New Hampshire’s Mount Monadnock in spring; while climbing in February in Joshua Tree National Park; during a November overnight hike of The Narrows in Zion National Park; on a chilly, October hike and scramble up 9,820-foot McGown Peak in Idaho’s Sawtooth Mountains; and on numerous local trail runs and rides and bike commuting.
The highly breathable Schoeller stretch-woven, soft-shell fabric blocks most wind, sheds light rain, and dries within minutes from body heat in temperatures ranging from the 30s to the 60s. The athletic fit leaves room for a midweight base layer and a light vest underneath, and the gusseted underarm panels let me reach high overhead without the jacket hiking up. The adjustable hood closes around your face to stay put in wind and when turning your head side to side, and fits over a helmet.
Along with the OR Helium Hybrid (below), the BD Alpine Start Hoody may be the most versatile piece in this review; but it’s not as warm as the Arc’teryx Atom SL or as weather-resistant as the Montane Minimum 777.
See my complete review of the Black Diamond Alpine Start Hoody.
What touches your skin matters. See my picks for the best base layers for any season.
Outdoor Research Helium Hybrid Hooded Jacket
$145, 8 oz. (men’s medium)
In the small field of hybrid ultralight jackets, OR’s Helium Hybrid Hooded Jacket stands out for both exceptional breathability and weather protection in a wide range of conditions. It kept me comfortable through weather events ranging from a violent, 20-minute thunderstorm with torrential rain and hail—I got home with my base layers only damp from sweat—to a wet April snowstorm, and cool, windy days of rock climbing and mountain biking.
The Helium Hybrid blends waterproof-breathable Pertex Shield fabric and taped seams throughout most of the jacket with OR’s highly breathable, water- and wind-resistant, stretchy soft-shell fabric in the side panels and undersides of the sleeves. The result is solid protection from precipitation where it tends to hit you—on the front, back, and head—with superior breathability where your body needs to dump it: in the core, underarms, and forearms. Multiple times, I sweated hard while trail running or riding, and the fabric moved moisture so well that my base layer got only somewhat damp and dried out under the jacket when my exertion level dropped. It features an adjustable hood that stays put in wind, a zippered chest pocket and two mesh-lined hand pockets, and lightweight, reasonably durable 30-denier ripstop nylon fabric.
While one of the heaviest pieces reviewed here, it’s arguably the most versatile—and one of the most affordable.
See my complete review of the Outdoor Research Helium Hybrid Hooded Jacket.
BUY IT NOW You can support my work on this blog by clicking any of these links to purchase a men’s or women’s Outdoor Research Helium Hybrid Jacket at moosejaw.com, ems.com, outdoorresearch.com, or rei.com.
Need a new rain shell? See my picks for “The 5 Best Rain Jackets For the Backcountry.”
Arc’teryx Atom SL Hoody
$229, 9 oz. (men’s medium)
The warmest and only insulated shell in this review, the Atom SL Hoody has been a go-to piece for me in situations as varied as backpacking in August in Canada’s Kootenay National Park and in October in Idaho’s White Cloud Mountains; scrambling a 10,000-foot peak in Idaho’s Sawtooth Mountains and hiking to the very windy summit of 10,243-foot Mount Washburn in Yellowstone National Park in September; and numerous times Nordic skate-skiing in temps in the 20s and 30s.
Essentially an ultralight wind shell with some strategically placed insulation, it delivers just enough warmth for being active in cool temps without causing you to overheat. Credit the fleece under the arms and 40 grams of insulation in the torso, but no insulation in the hood or on the outside of the sleeves, where there’s just windproof shell fabric that breathes reasonably well. Arc’teryx’s Coreloft synthetic insulation is very compressible, retains heat when wet, and dries quickly. The adjustable hood stays put on your head, with or without a helmet. Whether I was standing on a windblown 10,000-footer, carrying a backpack through the mountains in conditions that shifted frequently between warm sunshine and overcast with cold wind, or perspiring profusely while skate-skiing, the Atom SL keep me warm but didn’t make me too hot. It’s ideal for cool to cold temps or anyone who gets cold easily in moderate temperatures.
See my complete review of the Arc’teryx Atom SL Hoody.
Which puffy should you buy? See my “Review: The 10 Best Down Jackets” and
“Ask Me: How Can You Tell How Warm a Down Jacket Is?”
$140, 4.5 oz.
Possibly the lightest waterproof-breathable shell on the market today, the hooded Rainbreaker protected me through three hours of rain on a 27-mile, one-day traverse of Maine’s Mahoosuc Range in August; on a cool, windy morning camped at 5,000 feet in the Grand Canyon in May; and on chilly, windy spring days of climbing at Idaho’s City of Rocks and trail runs in the Boise Foothills.
The design is simple. The lightweight, 20-denier, proprietary waterproof-breathable fabric has a DWR treatment, seam taping in critical zones, a hood that adjusts using one hand, and one zippered chest pocket that it stuffs inside. Although some moisture accumulates inside when I’m sweating hard, it breathes well enough to never get uncomfortably clammy. While it lacks the technical hood and features of the jackets below, the affordable Rainbreaker delivers good performance for an ultralight shell, but only comes in men’s sizes.
Watch for my upcoming complete review of the Flylow Rainbreaker.
BUY IT NOW You can support my work on this blog by clicking this link to purchase a Flylow Rainbreaker at mountaingear.com.
Montane Minimus Stretch Ultra Pull-on and Jacket
$185 (Pull-on)/$205 (Jacket), 6 oz. (men’s medium pull-on)
While any ultralight wind shell or rain jacket offers versatility, the Minimus Stretch Ultra—which comes in pull-on and full-zip jacket versions—pushes the extreme low end in weight for waterproof-breathable outerwear. It’s one of the lightest rain jackets out there, appealing to hikers, ultralight backpackers, trail runners, and climbers who head out in cool, damp weather. I pulled on this six-ounce shell for bone-rattling cold wind on a dayhike in Glacier National Park and back-to-back, rim-to-rim dayhikes across the Grand Canyon, and in chilly wind and rain while scrambling peaks in Idaho’s Sawtooth Mountains, among other outings.
The waterproof-breathable Pertex Shield fabric repelled steady, light rain for a few hours in the Sawtooths and breathed well enough when hiking and scrambling steeply uphill off-trail in cool temps in the Sawtooths. The jacket hood has two-point adjustability, and the pull-on hood is not adjustable; still, I found the pull-on hood, which is elasticized in back and front, didn’t blow off in wind, stayed put when I turned my head, and fits smoothly under a climbing helmet. The small, flexible brim keeps light rain off your face, and the jacket and pull-on both stuff into a zippered pocket, packing down to the size of a large orange.
Waterproof but not as breathable as other ultralight shells, the Minimus Stretch Ultra is better suited to damp, cool dayhikes, backpacking trips, climbs, and long trail runs.
See my complete review of the Montane Minimus Stretch Ultra Pull-on and Jacket.
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The North Face Flight Series Fuse Jacket
$250, 5 oz. (men’s medium)
From a 20-mile, 4,500-vertical-foot, mid-September trail run-hike of the Alice-Toxaway Loop in Idaho’s Sawtooth Mountains, including a 1,400-foot, third-class scramble up 10,651-foot Snowyside Peak in chilly winds and temps that ranged from the low 40s to around 50° F, to hiking in the western North Carolina mountains in light rain and temps in the 50s in October, the 5-ounce Fuse Jacket shielded me from the elements while remaining one of the lightest, most packable ultralight shells you will find.
Unique to the Fuse Jacket’s design are perforated strips built into the 2.5-layer membrane, running down the back, sides, and underarms. These are not holes in the jacket fabric itself—so you don’t have wind whipping through it. Hold the jacket up to light and you can see the fabric is thinner where perforated. While TNF’s DryVent fabric breathes moderately well, sheds light rain, and cuts wind as well as any ultralight wind shell, the perforation allows air to pass through the fabric more easily. The Fuse got only a little clammy when I started heating up.
With very good weather resistance and just moderate breathability for an ultralight shell, The North Face Flight Series Fuse Jacket is best for cool-weather dayhiking, climbing, and running in wet climates, where you need protection from wind and light rain.
See my complete review of The North Face Flight Series Fuse Jacket.
BUY IT NOW You can support my work on this blog by clicking either of these links to purchase a men’s The North Face Flight Series Fuse Jacket at moosejaw.com or a women’s Flight Series Fuse Jacket at moosejaw.com.
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