The 4 Best Sustainable Ultralight Rain Jackets for Backpacking So You Can Stay Dry Without the Weight
Looking for an ultralight rain jacket that won’t weight you down on your next backpacking trip or day hike? These are some of the best of the best if you’re looking to cut weight from your pack but still stay dry and happy during soggy expeditions. Bonus: All of these are PFAS-free (read about why that’s good here).
Why Choose an Ultralight Rain Jacket?
Let’s be clear: ultralight rain gear for backpacking isn’t for everyone. It’s lighter, sure, which means less weight in your pack when the sun’s out, but ultralight rainwear can also be more delicate and is doesn’t always boast the same reliable waterproof/breathability ratings as more conventional rain jackets.
Ultralight rainwear isn’t always the best choice for extreme conditions and days-long deluges. Or when you’ll be wearing the jacket on warm days during high-effort activities since ultralight gear doesn’t typically have zippered vents for dumping heat (though they’re often similarly breathable thanks to waterproof-breathable membranes).
They typically have fewer features and bells and whistles like pockets or hem and cuff adjustability but still cost nearly as much as burlier jackets.
That said, what they lack in features they make up for in packability and weight savings. Especially if you’re the type who’s likely to forego packing a “just in case” rain shell because of the bulk and weight. Bonus: They also make great windbreakers.
What are Ultralight Rain Jackets Best For?
So what types of trips and activities are ultralight rain jackets generally BEST for?
- Ultralight backpacking
- Day hikes where rain is a possibility
- Trail running
- Backpacking when precipitation is a possibility
- Light-medium precipitation
What are UL rain jackets NOT as well-suited for?
- Bushwhacking expeditions
- Days of pouring rain in the forecast
- When the option to vent is of utmost importance (when you sweat too much inside a jacket it can make you feel damp and clammy)
How to Care for Your Ultralight Rain Jacket
Remember, if your rain jacket––ultralight or otherwise––isn’t shedding water like it used to, it may just need washed and re-waterproofed with an appropriate technical gear detergent like Nikwax (read about how to wash rain gear here). And if you do damage an ultralight shell, repair it, don’t replace it.
How We Test
We’ve tested and used dozens of rain jackets over the years (conventional and ultralight) and know what makes a solid, reliable ultralight shell for hiking and backpacking.
We tested each of these rain jackets on short and long hikes, on rainy walks around the neighborhood, took them traveling around the U.S. and beyond, and assessed features, fit and functionality to see where each shined and where they fell flat.
Ultralight Rain Jackets for Backpacking
Outdoor Research Helium UL: For Ultralighters with Style
Crafted with 2.75-layer construction (most rain jackets are 2.5 or 3), this bright, ultralight rain jacket is perfect for unpredictable weather, spring showers, and backpacking and hiking trips where light rain is in the forecast but you definitely also want a light shell to protect from the cool evening breeze.
The Helium UL is just the thing. Plus, it got an upgrade from previous versions (that didn’t include “UL” in the moniker). While we still loved the former generation for ultralight rain protection, it didn’t breath as well, sometimes felt clingy, and needed washed and re-waterproofed regularly.
But the new Toray Dermizax™material is more textured, so doesn’t feel as clingy, seems more durable, and breathes a touch better, too. What’s more, we loved the new features in the jacket, including a wire brim, zippered hand pockets in the women’s version (men just get a single chest pocket), and an adjustable bungee in the hood and hem. In fact, it’s a rare UL jacket that actually has hand pockets!
The hood fits well and stays in place, the jacket packs up small into its own pocket, and it acts as an excellent windbreaker, too. It’s on the fitted side, so I sized up, which left plenty of room for a layer like an ultralight fleece or grid fleece underneath. Bonus: it comes in the most color options for those who like to keep it vibrant on the trail.
It’s not the jacket we”ll reach for for backcountry expeditions when we’re certain that days of pouring rain are about to ensue, but for a few hours of showers a day or for a “just in case” jacket, we’re obsessed. In fact, it’s the one we brought on a three-day backpacking trip in Belize where it poured for a couple hours one day and we stayed perfectly dry.
Pros:
- Two zippered hand pockets (women’s version)
- Packs into it’s own pocket
- Comes in several brights and neutrals
- Wire brim
- Adjustable hood
Cons:
- No hand pockets in men’s version
- Brim could extend farther out
How it’s sustainable: Infinite Guarantee, founding member of the Outdoor Industry Association (OIA) Climate Action Corps, 100% of energy usage in North America originates from renewable energy facilities.
- Weight: 5.6 oz/ 159 g
- Waterproof Rating: 20k/20k
- Price: $225
Rab Phantom Jacket: For Extreme Ultralighters
When size and weight matter most, we reach for the Rab Phantom Jacket. It packs up smaller and weighs less than any other shell on this list. Made of 2.5-layer Pertex Shield, it’s virtually weightless on or in the bottom of a backpack or running vest.
We loved that the jacket packed into a built-in pocket in its own hood that also functioned as venting thanks to perforations under the flap that kept out rain but aided in dumping a touch of heat (not that it made a massive difference in breathability). It was crazy easy to cram into a hip pack on short hikes or bike rides around town when an extra layer might be required later in the day.
The material was stupendously lightweight and the fit left just enough room for layering over a snug layer like an ultralight fleece or grid fleece. Plus, on a recent backpacking trip where it rained steadily for several hours straight, we were all dry underneath (if not a bit steamy after extended uphills since there are no vents except in the hood).
Speaking of the hood, it was beautifully functional. A small wire in the brim offered a solid customizable fit and the chin came up just high enough to offer protection without feeling obstructive. Elastic cuffs with extensions on the top of the hands were also a welcome feature. Take note, though: there’s not a single pocket on the Phantom. That didn’t bother us when wearing it with a backpack and hiking with poles, and is par for the course on extreme UL gear, but may not appeal to everyone.
There are zippered hand pockets on the similar Phantom Mountain Jacket for those willing to sacrifice a few ounces for extra functionality, but honestly, when packability and light weight were the priority, we didn’t miss the pockets.
Pros:
- Most ultralight
- Tolerably breathable
- Packs into the hood
- Adjustable hood
- Venting in hood helps prevent billowing in wind
Cons:
- No pockets
- Only comes in two colors
How it’s sustainable: 43% total recycled materials. In 2025, 76% of Rab’s production volume was manufactured in factories with renewable energy, Rab is a Fair Wear Leader, and operates a repair center for gear. Rab is also a B-Corp.
- Weight: 3.7oz/104.5g
- Waterproof Rating: 20k/20k
- Price: $225
La Sportiva Aequilibrium Lite GTX Jacket: For Reliable Protection in Any Weather
The Aequilibrium Lite GTX from La Sportiva is a capable Gore-Tex jacket made with an ePe (PFAS-free) membrane, so you know it can stand up to some elements. In fact, this is the UL rain shell we’d choose, no contest, for trips where we’re expecting serious downpours on the regular. With an elasticated hem and cuffs, it’s also excellent at sealing out water.
In fact, on a recent very windy hike in the rain, the high collar (complete with soft chin guard) and adjustable hood were excellent at keeping out blowing precipitation when battened down. That’s thanks in part to the small brim that extends over the forehead an inch or two coupled with an elasticated section that keeps the hood snuggly in place on your head.
It is a touch heavier than some other ultralight rain jackets, but still far lighter than traditional rain shells while offering nearly the same impenetrable waterproof protection. In fact, it may be the perfect jacket for long wilderness jaunts and poor weather conditions where you want the most protection for the least bulk. Bonus: it functions as more than an ultralight rain shell.
In fact, a rep from the brand said he takes this jacket backcountry skiing on warmer days when he wants to keep his pack light but still needs waterproof protection and a windproof layer for the downhills. It’s light and packable enough to cram in the side pocket of a backpack and burly enough to handle minor falls in the snow.
The jacket does run on the large side, so don’t be tempted to size up. We found that ordering our regular size still offered plenty of room for layering bulkier layers like a fleece sweater or lightweight insulated jackets. The sleeves were plenty long and the durability and protection were paramount. Do keep in mind: because it’s GORE-TEX, it does come with a higher price tag than your average UL jacket.
Pros:
- Single chest pocket large enough for an iPhone
- Gore-Tex ePe waterproof membrane
- Helmet-compatible hood
- Durable
- Multi-functional
Cons:
- No adjustable hood, hem or cuffs
- Only comes in two colors
- Expensive
How it’s sustainable: Membrane is made of 100% recycled materials, as is the inner hood. Brand is Climate Neutral Certified. Boulder, CO facility is zero waste and Italy headquarters uses 100% renewable energy.
- Weight: 184 g / 6.4 oz
- Waterproof Rating: 28k
- Price: $309
Mammut Duncan Light HS Hooded Jacket: For Built-in Ventilation
Looking for a capable, comfortable rain jacket to ward off the elements that even offers ventilation? The Mammut Duncan Light HS jacket might be the one. It’s sleek, slim, has a long hem for extra protection and elastic cuffs to help seal out moisture.
The 2.5 layer Mammut DRY ACTIVE technology kept us dry when gardening in the yard on rainy days and on short hikes, but it’s also tolerably breathable. It’s rendered even more so thanks to a front closure snap at the chest that allows you to fully unzip the jacket but snap it closed so it stays put but you enjoy more airflow. This was great for warm days when precipitation only involved a light drizzle and we were working hard hiking uphill.
The hood was nicely fitted when short-haired testers wore it, but when one tester with long hair tried the jacket with her hair in a bun, she found the bill didn’t quite extend far enough over her face to offer solid protection. So those with long hair or full volume hair may prefer a jacket with a roomier hood or one that’s helmet-compatible.
But the jacket material was soft and impressively quiet and we appreciated the large chest pocket that was plenty roomy for a iPhone Max but also functioned as a stuff sack for the jacket during transport. It has an athletic fit that’s a bit more slim-cut, so if you like your jackets on the roomy side to accommodate bulky layers, consider sizing up.
Pros:
- Front closure snap for ultimate venting
- Quiet material
- Large chest pocket
- Packs into its own pocket
Cons:
- Non-adjustable, low-volume hood
- Only available in a couple colors
How it’s sustainable: Jacket main material made of 100% Polyamide (recycled), Bluesign product, Fair Wear Certified.
- Weight: 175 g / 6.2 oz
- Waterproof Rating: 20k
- Price: $189
Bottom Line
For solid protection without the weight, ultralight rain jackets are where it’s at whether you need a packable rain jacket for travel, an ultralight kit for backpacking, or a multi-functional shell for wet-weather trail running. Any of these will keep you dry and having a good time outdoors, even if the skies start dumping. So gear up and wander on (no matter the weather).
