Over the past few years, the summit of Snowdon has become so popular that you might think you’d need to go up in deepest, darkest December in order to get it all to yourself. At least, that’s what I figured the first time I ever climbed Yr Wyddfa in winter. We got to Pen y Pass just after 6am because, as everyone knows, the car park gets notoriously busy. Not when it’s freezing cold, it turns out. It was deserted. That set the tone for things to come, as we hardly saw another soul all the way to the summit.
It proved to be a memorable mountain day, though a pretty testing one too. Because when you’re climbing Wales’ highest peak in full winter conditions with no-one else around, you need to rely not just on your own skills and experience, but also your kit.
Crunching up the Pyg Track in crampons, with ice axes in hand and big packs on our backs, I was glad we’d thought to take not only our winter hardware but also plenty of extra layers. It was seriously cold, even when working hard. The wind howled as we made our way up to the marker stone on Bwlch Glas.
Fumbling with thick gloved hands, we fished around inside our packs for buffs and goggles to fend off the stinging spindrift. There was no sanctuary until we reached the shuttered entrance of the summit café, long closed for winter. We hunkered down in the doorway for a few minutes and quietly toasted our efforts with swigs of hot chocolate from a flask. Swaddled in a big belay jacket, I thought to myself that I’d never been so grateful for having the right kit.
What point am I trying to illustrate with this little tale? Well, those are precisely the sorts of days when a big, tough pack is the perfect choice. Ideally, around 40-50 litres in order to carry all the gear you’ll need. Here are our top picks for truly memorable winter mountain adventures.
Key features to look for in 40-50 litre winter daypacks
Function and design: Mountaineering packs generally have a slim, long shape, with minimalist external features and a close-to-the-body fit – a no-nonsense design that’s ideal for technical activities in winter. Hiking packs tend to be slightly wider, with side pockets, intricate features and high-tech back systems.
Lid: The lid covers the top main opening to the rucksack. Some lids are fixed to the backpack while others are detachable with a ‘floating’ design. A current trend is towards lidless backpacks with roll-top closure.
Weather resistance: Backpacks are usually made from water-repellent materials and the fabrics will often withstand a heavy shower or two. But they aren’t infallible (particularly when seams aren’t sealed or external zippers are exposed). Some packs come with waterproof covers, while others are better paired with a waterproof pack liner.
Back panel ventilation: Back panels made from perforated foam or padding carry the load directly next to the body. This approach is comfy and stable, but sweaty. Mesh back panels, conversely, hold the pack’s bulk away from your back, thus improving ventilation – but the load can feel like it’s levering away from you.
Pockets: Zippered hipbelt pockets are handy for stashing gear you’re likely to need on-the-go. Internal zippered pockets are great for car keys or a wallet, and elasticated side pockets are perfect for a water bottle. Some packs also feature large stuff pockets made from stretchy mesh.
Straps: External compression straps, webbing loops, toggles, and bungee cords can be used for attaching items such as ice axes, trekking poles and crampons.
Shoulder straps: Shoulder straps should fit comfortably and be adjustable to your body shape. Padding thickness and contouring will affect the overall load-bearing comfort of shoulder straps. A sternum strap enables lateral connection of the shoulder straps to boost comfort and stability, while load lifter straps adjust how close the upper part of the backpack is to your back.
Back system and hipbelts: All backpack systems have the same goal: to transfer the load to your hips and provide a comfy carrying experience. For heavier loads a stiffer frame is needed, as is a thickly padded, pre-curved belt that wraps snugly around your hips, bearing weight without feeling excessively tight. Manufacturers often state a maximum load (kg) a backpack is designed to carry.
Back length: It’s vital to pick a backpack with a size appropriate for your torso length. Trying on a loaded pack is the easiest way to do this. Some backpacks come in various length options, some are adjustable via webbing straps or Velcro, and some come in only one size.
The best 40-50 litre winter daypacks
Mammut Trion 50
Verdict: A tough, versatile all-round pack that carries well under load, accepts plenty of kit and has very useful features, including quick access to the main compartment.
Features 5/5 | Fit 4/5 | Comfort 5/5 | In use 5/5 | Value 3/5
Overall score: 88%
Pros: Lightweight, tough, comfortable with a heavy load, features aplenty
Cons: One size and non-adjustable back length
Mammut’s Trion Spine 50 is a previous ‘Best in Test’ winner in this category. The Trion 50 is essentially the same design, though with a simpler fixed back system that forgoes the brand’s unique double pivoting ‘Active Spine’ tech. So, you don’t get the same custom fit or luxurious carrying comfort – but on the flipside, this version is much lighter and cheaper.
It also adds convenient access to the main body via a big, U-shaped rear zip that runs around the back panel, just below the shoulder straps. We’re starting to see this feature on a few of the latest packs to hit the market, and it’s a bit of a gamechanger for grabbing extra layers fast. That’s always good when you’re out in winter conditions.
The back panel and harness are lightly padded and well ventilated. The fabrics are tough, with a Cordura nylon base, and there is ample useful storage. We particularly like the big, zipped front pocket.
The pack also has the ability to carry a rope, ice axe, trekking poles and even skis. It features dual side compression straps, hydration compatibility and can be overstuffed thanks to an extended drawcord collar and a floating lid.
If we’re being fussy
This pack only comes in one size and the back length (18in) isn’t adjustable, so it’ll either fit you or it won’t. An inner lid pocket would also be good.
Weight 1.57kg (1.24kg stripped) | Volume 50 litres | Sizes One size | Main fabrics 840D and 210D fabric with Cordura reinforcements | Sustainability PFC-free DWR, Mammut a Fair Wear Foundation member
Salewa Ortles Guide 45
Verdict: A technical pack that is tough yet light, and versatile enough for year-round use. But the harness and back system won’t suit all.
Features 4/5 | Fit 3/5 | Comfort 4/5 | In use 4/5 | Value 5/5
Overall score: 80%
Pros: Easy access to main compartment, tough, lightweight, suitable for year-round use
Cons: One size, back panel can be cold and doesn’t shed snow well
This robust pack is built from high-tenacity double ripstop nylon, with a reinforced base. The fabric is 100% recycled too. But as well as being tough, it’s lightweight and weatherproof.
There’s a roll-top closure beneath a floating, double buckle lid. The lid can be removed to save weight. That would mean losing the lid pocket, but there is a secondary zipped top pocket with a key clip inside, plus a large, zipped front pocket.
The main compartment has a two-way, water-resistant side zip for quickly grabbing or stowing an extra layer. It’s also hydration-compatible, with other features like side compression straps, a rope strap, ice tool/trekking pole loops and ski holders.
It feels stable when loaded, with a plastic framesheet and a U-shaped metal stay to add structure and rigidity. But the most striking design elements are the harness and back system, which feature split shoulder straps and a heavily vented ‘Dry Back Contact’ panel. It’s a good weight-saver and makes for great airflow.
As such, you could use this pack year-round, which adds to its overall value. On the other hand, we do think the design entails a few compromises
If we’re being fussy
The floating hip fins aren’t the most supportive. We found that the split straps tend to fold over when you’re getting the pack on and off, while for winter use the vented back panel gets chilly and accumulates snow and ice. This pack only comes in one size too.
Weight 1.38kg (0.95kg stripped) | Volume 45 litres | Sizes One size | Main fabrics Recycled 210D ripstop nylon | Sustainability Made from recycled nylon, Salewa a Fair Wear Foundation leader
Osprey Mutant 52
Verdict: A conventional but well-proven pack that easily accommodates all the extra gear needed for big winter adventures, though other packs are slightly more versatile.
Features 4/5 | Fit 5/5 | Comfort 5/5 | In use 4/5 | Value 4/5
Overall score: 88%
Pros: Good fit, comfortable and supportive, very durable
Cons: No rear/side access, quite pricey
Osprey’s Mutant 38 is a Trail favourite, but it is a couple of litres short of our 40-50 litre ‘sweet spot’ for a winter pack. So, this time around we went bigger and tested the newly updated Mutant 52.
The design hasn’t changed much, but the materials have. Fabrics are now bluesign-approved and made from recycled content, with a PFC-free water-repellent finish. The pack retains its reinforced double base and robust back panel, so it’s still just as tough. It’s a stable load-hauler, too, thanks to a removable plastic framesheet that is reinforced with two angled aluminium stays.
It’s a unisex design but comes in two back lengths to ensure a good fit, while the harness and hip fins are nicely padded without feeling bulky. This ensures it’s comfy but also streamlined.
The front panel has attachment points for trekking poles or ice axes, with removable straps for carrying crampons. There’s also an optional helmet net in the lid.
Inside the main compartment you get a hydration sleeve and a useful mesh pocket (though we wish the key clip was located here instead of in the outer lid pocket). The pack is easy to load thanks to a wide mouth drawcord opening.
If we’re being fussy
The design is a traditional top-loader with no rear or side access to the main compartment. There’s still nowhere to tuck away the dangling rope strap when not in use. And the price has jumped up, so the Mutant packs aren’t quite the value proposition they once were.
Weight 1.54kg (1.01kg stripped) | Volume 52 litres | Sizes S/M, M/L | Main fabrics Bluesign-approved recycled 210D nylon | Sustainability Bluesign-approved, recycled fabric, PFC-free DWR
Deuter Freescape Pro 40+
Verdict: Easy to load and equipped with masses of on-board storage, this versatile pack has some unique and very useful features.
Features 5/5 | Fit 4/5 | Comfort 3/5 | In use 4/5 | Value 4/5
Overall score: 80%
Pros: Plenty of storage space, surprisingly versatile, rear-access zip
Cons: Doesn’t bear heavy loads as well as others
Though primarily designed for ski mountaineering, this pack works well for winter walks and scrambles too.
Despite being nominally smaller than other packs on test, it swallows plenty of kit and is positively laden with useful on-board storage. There are two generous front pockets, a hipbelt pocket, twin lid pockets and a side security pocket for a phone or GPS unit.
The roomy main compartment has a double drawcord collar with a mesh hanging pocket and a hydration sleeve inside. The top lid pocket even has a microfleece-lined pouch, ideal for stowing snow glasses or goggles.
There are also attachment points for ice axes and trekking poles, plus ski holders, a rope strap, a detachable helmet net and removable webbing straps for lashing crampons. Deuter really has thought of everything here.
We also like the fact that, just like the Mammut and Berghaus packs on test, it has a U-shaped zip around the back panel. This ensures fast, easy access to the main body.
Fabrics are tough enough to take plenty of hammering, while being 100% recycled and bluesign-certified – both big ticks for sustainability. There’s also a dedicated women’s version of this pack, the Freescape Pro 38+ SL.
If we’re being fussy
It’s lighter-framed than the other packs here, so doesn’t carry quite as well. The back padding and straps supposedly use a snow-shedding fabric but seem to soak up a lot of moisture, which feels cold and clammy.
Weight 1.51kg (not strippable) | Volume 40+ litres | Sizes One size (women’s Freescape Pro 38+ SL available) | Main fabrics Bluesign-approved recycled 235D, 420D, and 630D| Sustainability Bluesign-approved, recycled main fabric, Deuter a Fair Wear Foundation leader
Berghaus MTN Guide 45+
Verdict: A tough technical pack built to handle winter conditions with ease – but the design prioritises performance over comfort.
Features 5/5 | Fit 4/5 | Comfort 3/5 | In use 4/5 | Value 4/5
Overall score: 80%
Pros: Two sizes, customisable lid, really tough, loaded with winter features
Cons: Other are more comfortable, technical features are overkill for some
This is a true ‘bomber’ mountain pack from Berghaus’ technical Extrem collection. It’s extremely tough and weatherproof, with a main body made from TPU-coated 400-denier nylon. This fabric is 100% recycled, as is the plastic hardware. Other panels are made from dope-dyed ripstop polyester to reduce water waste. TPU is also more eco-friendly than traditional water-repellent finishes. It’s great to see top-end kit being manufactured sustainably.
The pack has a streamlined look but is fully featured. Like the Mammut and Deuter packs on test, it has back panel zipped access, so you can get to your gear without having to unstrap kit that might be lashed to the front and sides of the pack. It’s able to carry a rope, ice axes, trekking poles and even skis. There’s a removable helmet net, plus twin grab handles and multiple lashing points.
Inside, there’s a big hydration sleeve and a security pocket. You get two more pockets in the lid too. The floating lid can be removed to save weight, and – cleverly – the pack can then be closed, roll-top-style, giving a more weatherproof seal than just relying on a drawcord.
It carries reasonably well with a full load, and comes in either short or regular back lengths for a better fit.
If we’re being fussy
The more technical features will be overkill if you just need a big pack for winter hillwalking. The low-profile harness and hip fins are designed for freedom of movement rather than plush carrying comfort.
Weight 1.62kg (1.15kg stripped) | Volume 45 litres | Sizes Short or regular | Main fabrics Recycled 400D nylon, 600D polyester with TPU coating | Sustainability All nylon is recycled, polyester is dope-dyed, PFC-free DWR
Black Diamond Mission 45
Verdict: A workhorse of a pack that is stable, durable and comfortable, though its technical features are better suited to winter mountaineers than winter hillwalkers.
Features 4/5 | Fit 4/5 | Comfort 5/5 | In use 4/5 | Value 3/5
Overall score: 80%
Pros: Hardy, excellent lid design, two back lengths, great features for mountaineers
Cons: Heaviest on test, strict alpine focus won’t suit all hillwalkers
This is a big, burly pack with a technical focus on Alpine climbing and mountaineering, which is reflected in the design and features. It is fitted with pick pockets and metal ‘dogbone’ hardware to fit through the head of an ice axe. There’s also an external crampon pouch and a tuck-away rope strap. Luckily, most of those elements transfer well to cold-weather adventures in the UK too.
It’s certainly tough enough for Scottish winter epics, being made from heavy-duty ripstop nylon. The conventional top-loading configuration has a floating lid, twin buckles and a double drawcord closure with an extended collar. This makes the pack easy to overstuff when carrying a full complement of winter gear.
The lid design is excellent, with inner and outer pockets. The lid is even big enough to take a climbing helmet. The deep main compartment has an expanding hydration sleeve, plus an extended two-way side zip that makes it easy to dig around inside without having to unbuckle the lid.
It is available in two back lengths and, while the back system is fairly straightforward, it makes for a comfortable carry. Ergonomic shoulder straps offer enhanced mobility when scrambling or climbing, even with a heavy load.
If we’re being fussy
There are no lower bungees or side wand pockets, so it is awkward to carry trekking poles. This is also the heaviest pack on test – though you can strip weight by removing the frame and hip fins.
Weight 1.71kg (1.25kg stripped) | Volume 45 litres | Sizes S/M, M/L | Main fabrics 420D ‘BD X-rip’ nylon with UTS coating | Sustainability No specific reference
Rucksack care and maintenance
The technical fabrics used to make rucksacks are tough and durable, but the right cleaning products are needed to maintain their performance. With rucksacks, we recommend either Grangers Footwear and Gear Cleaner, or Nikwax Tent and Gear SolarWash.
Read our in-depth guide on how to care for your rucksack for everything you need to know about rucksack care.