Atlanta Trails shirts: locally made & inspired by great Georgia adventures

The Osprey Stratos 24 and Sirrus 24 are ultra-breathable backpacks, ventilated for warm-weather day hikes in the South. Our trail-tested review.

We’re avid hikers, backpackers, and cyclists. And we’re longtime fans of Osprey’s backpacks for all of our trail sports, thanks to Osprey’s thoughtful design, excellent craftsmanship, and an all-around great fit. Our adventures take us from barrier islands on the Atlantic, like the outstanding Cumberland Island, to the highest summits in the Blue Ridge Mountains, like the towering Mount Mitchell. And we hike in temperatures ranging to downright chilly to the South’s legendary scorching heat and high humidity.

When the temperatures rise, there’s nothing worse than a heavy backpack sticking to our backs for hours, radiating our body heat back at us and making us all the more uncomfortable. So when we found the Stratos 24 and women’s Sirrus 24 backpacks, we were pretty stoked: Osprey designed these bags to increase ventilation and decrease heat, a winning combination for the South.

Osprey Stratos 24 and women's Osprey Sirrus 24: our favorite ventilated day pack for warm-weather hikes

This innovative backpack from Colorado-based Osprey features a hip belt and load-supporting frame, which adds to its weight, but also works wonders to help decrease the pack’s apparent weight. The pack’s frame is curved, arching it away from our backs and creating a breeze-catching tunnel. Against our backs, a perforated mesh panel helps prevent sweaty sticking and works with the curved frame to keep us cool. And with a roomy 24 liter volume, spacious enough for our camera and favorite day hike gear, we’re fully won over.

Osprey Stratos 24 and Sirrus 24: our trail-tested review

We’ve hiked hundreds of miles in these packs, and they’ve been our warm-weather go-to backpack for years. Year-round, the curved, lightweight aluminum frame and open perforated back panel leave space for a ton of airflow between the pack and our backs. While they’re perfect for warm summertime hikes in the South, this tech is equally great on cold-weather hikes. In the winter, the pack’s ventilation helps to minimize sweat on a climb and prevents the subsequent extreme chill once we reach a breezy summit and take off our backpacks to soak in the view. The pack’s thoughtful design results in an incredible amount of ventilation.

Osprey Stratos 24 and women's Osprey Sirrus 24: our favorite summertime backpack increases ventilation with a perforated back panel and curved frame

On the trail, the pack’s feel is lightweight and comfortable. Its design is streamlined, spanning more depth than width, which helps for scrambles through tight brush or squeezes through tight rock. And the backpack is durable: despite heavy use and some heavy loads, the packs have held their suspension, comfort, shape, and stitching rather flawlessly.

The curved aluminum frame slightly reduces the pack’s volume, but it still retains a roomy 24 liters of cargo storage. The interior is roomy enough to stow gear for an average day hike, including water bottles, safety and wayfinding gear, extra layers, a waterproof jacket, lunch, and snacks. For shorter treks, we usually pack a few Nalgene bottles for water, but on longer adventures, we love the convenience of using a hydration pack. The internal hydration pack storage sleeve on the Sirrus 24 and Stratos 24 pairs really well with our lightweight (and frameless) Osprey Hydraulics LT hydration reservoirs. An exit port on the pack makes routing the hydration pack tube easy, and elastic bands on the backpack’s straps offer quick-access storage for the reservoir’s bite valve.

Our favorite day hike backpack: the Osprey Stratos 24 and women's Osprey Sirrus 24, our trail-tested review

We use the zippered pocket on the top of the Stratos and Sirrus to store gear for quick access. The top pocket is roomy enough to store a base layer for warmth, a compass, a small first aid kit, keys, and a Clif Bar or two. And on the sides of the pack, two side pockets keep bear spray and water bottles within an arm’s reach. The side pockets are also useful for carrying a tripod – they fit my Gitzo GT1544T Traveler tripod with two tripod legs in the pocket, and the pack’s adjustable loop clenching the tripod’s top.

The backpack’s straps and hip belt are lightweight and perforated but thick and cushy, helping to keep us cool, dry, and comfortable. The straps and belt are quickly adjusted with a pull of a strap, allowing for quick on-trail adjustments after a few miles. And the suspension system works wonders when the loads run heavy, keeping the weight evenly distributed and comfortable.

The Osprey Stratos 24 and Sirrus 24 backpacks feature perforated, well-padded straps for cool comfort on warm-weather hikes

Weighing in at 2 lbs 4 oz, the Stratos 24 and Sirrus 24 aren’t ultralight: the curved frame and suspension do add some weight. But on the back, this pack feels lightweight and comfortable, and it balances its cargo weight well. After a few miles on the trail, it’s clear that the pack’s incredible comfort outweighs its extra weight. A ten-pound load in the Sirrus 24 or Stratos 24 feels comparatively lighter after a few miles than in any of our lighter-weight backpacks.

Our favorite summer backpack for the South: the Osprey Stratos 24 and Osprey Sirrus 24 day packs are ventilated to keep us cool on the trail

The Stratos 24 and Sirrus 24 design packs additional features, including a rain cover that’s great for protection in an unexpected downpour. Their large zipper pulls allow for fast-grab access to the pockets. An integrated trekking pole loop is handy for pole or tripod storage. Small hip belt pockets offer quick access to small gear, like a handheld GPS, a mobile phone, or a Clif Bar. The extra pockets add some extra weight compared with a lighter-weight pack, like the Osprey Daylite, but offer quick-grab convenience when we’re on the move.

Osprey Stratos 24 and Sirrus 24: review wrap-up

The Osprey Stratos and Sirrus packs use an innovative ventilation system to increase breathability on warm-weather trail days, and the suspension and padding remain comfortable on 12+ mile hikes. We thoroughly love the design, comfort, stability, and breathability of this pack, and it’ll be with us for many future adventures.

So where can I find them?

Some links on Trailful are affiliate links, which means that the merchant might pay us a commission if you purchase a product after clicking our links, at no extra cost to you. We only recommend gear that we personally use and love.
Thanks for your support! - the Trailful crew

Rob Sollie

Rob Sollie fell in love with the outdoors while growing up in Montana near Glacier National Park. Since he moved to Atlanta in 2001, he’s made it a mission to find great outdoor adventures in Georgia and throughout the South. Rob’s favorite trails include the Conasauga River Trail in Georgia and the Deep Gap Trail at Mount Mitchell near Asheville.