Best insulated winter jackets for 2024: big warmth

Designed as a highly technical down jacket primarily designed for alpine use, the Mythic Ultra is all about maximum warmth for minimum weight. But we wondered if it’s worth it for most winter hillwalkers.

Well, we found that if you’re out in the hills in deep snow, its impressive warmth is very welcome indeed. The same goes for sub-zero wild camps.

The Mythic Ultra tips the scales at just over 500g and, being filled with 900-fill goose down, it’s highly compressible and takes up minimal space in a pack. The goose down has a Nikwax hydrophobic treatment to improve moisture resistance. Don’t mistake that for a silver bullet but we found it does help fend off moisture.

The jacket is constructed with stitch-through baffles on the arms and hood but offset box-wall baffles around the torso to maximise down loft and eliminate cold spots. It also has a secret weapon against the cold: an inner heat-reflective layer called TILT (Thermo Ionic Lining Technology).

We’ve previously tested it in Rab sleeping bags, and it definitely makes a difference to overall warmth. This jacket’s warmth-to-weight ratio is amazing, but there are trade-offs with this. The main one is that the superlight outer shell is tissue-thin, so treat it with care.

The jacket comes in both men’s and women’s versions, both of which are nicely cut. We liked the extended sleeves and a drop hem that ensures good all-round coverage, while dual hem drawcords and elasticated cuffs ensure a snug seal. Hand pockets are nice and cosy too. For a baffled down puffer, it offers surprisingly good mobility, though the jacket’s loft means this is really a standalone insulator, not one to wear over or under a shell.

Check out the women's version here

With this midweight synthetic insulated jacket, Mountain Equipment has backed its own materials rather than using Gore-Tex or Primaloft branded fabrics and fill.

So, the Shelterstone employs ME’s own 40D Drilite Loft ripstop nylon shell and 100% recycled 115gsm polyester Polarloft sheet insulation throughout. Avoiding the big names keeps the price tag slightly more affordable. But we found it’s still a stellar jacket, being windproof and water-resistant, coping well with light rain and snow.

At 600g, it’s heavier than the Rab Mythic Ultra, but still packs away into a neat little stuff sack that fits easily in a winter pack. It comes in both men’s and women’s sizes and is easy to throw on over a mid-layer and a winter hardshell.

We liked how the Shelterstone offers good all-round coverage, with nice long sleeves with cuff tabs, plus a drop tail with dual hem adjustment. The hood fits over a climbing helmet, but still cinches in tightly over a bare head, with three-way adjustment.

It has a small, stiffened peak and a two-way main zip with an extended collar that zips right up to the nose. Hand pockets are insulated and lined with microfleece. The result is a very cosy and protective overlayer. Other practical storage includes inner and outer zipped chest pockets, plus a stretch mesh inner dump pocket.

There’s almost nothing to criticise here, especially at this price – though obviously, if you spend more, you can get a jacket with superior warmth-to-weight.

Check out the women's version here

A dependable down jacket is a true investment because of its potential to last a lifetime. Nevertheless, often the upfront cost of a thick winter down jacket can be hard to stomach.

Kathmandu (a New Zealand outdoor gear brand) has cornered the down jacket market in the antipodes (seriously, in New Zealand and Australia in winter, everyone is wearing a Kathmandu down jacket). After our testing, it wasn't hard to see why.

The Epiq is filled with a generous helping of 600-fill down and is brilliantly warm in sub-zero temperatures. Obviously, the insulation is key to that, but the Epiq has a number of useful features to boost warmth like its adjustable hem and hood, internal stretch cuffs, and box baffles.

But frankly, we were most impressed with the Epiq because it doesn't sacrifice sustainability credentials even though it significantly undercuts many rivals on price. Its Pertex Quantum Eco outer is fully recycled and bluesign-approved; Kathmandu itself is a certified B Corp; and the use of RDS down is a given.

It's not an especially 'technical' jacket like the Rab Mythic Ultra, for example. The Epiq misses out on a hydrophobic down treatment and very high fill power down. But the outer fabric, for example, isn't as delicate as that used on the Rab Mythic Ultra. Meanwhile, the Epiq has a good range of pockets, and also comes in a non-hooded version, which is £25 less. It comes in plenty of neat colourways too.

Check out the women's version here

Fjällräven’s Keb range is designed for ‘technical trekking tours’. When it comes to insulating layers like this classic hooded down puffer, that means the focus is on light and compressible warmth combined with long-term durability. We found this jacket delivers on all counts.

It uses a completely recycled nylon shell, with a PFC-free durable water repellent treatment that can handle light rain and snow. The shoulder panels, lower back and forearms feature double layers of fabric to provide extra protection from general wear and tear.

Meanwhile, stitch-through baffles house 150g of 800 fill power goose down. This delivers a good level of warmth, certainly cosy enough for winter use in our hills and mountains. However, the price is high given that this jacket uses a slightly lower fill power down than the other down jackets on test. And the down itself has no moisture-resistant treatment.

Nevertheless, we think it’s an extremely comfortable jacket, with great all-round coverage and some excellent features. This includes a profusion of useful pockets inside and out – seven in total.

The two-way main zipper is backed with a full-length baffle that secures with press studs to combat draughts. We really liked the excellent dropped tail, the snug-fitting hood with rear volume adjustment, and a nice high collar that extends up to the nose.

An elasticated drawcord hem and bound cuffs create an effective weatherproof seal too. With all the hatches battened down, the jacket feels very warm indeed, yet the design is versatile enough to work underneath a shell or over all your other layers.

Check out the women's version here

This is a classic belay-style jacket, developed with input from mountain search and rescue teams. It uses a well-proven approach to conquering the cold, packing a tough outer shell chock-full of synthetic sheet insulation.

But there’s plenty of tech at work too. It employs Helly’s own Lifaloft fill in combination with PrimaLoft Gold fibre balls and a conductive graphene lining, for superior warmth. This is zoned to protect your core and we found it works brilliantly.

Meanwhile, the outer shell is another Helly innovation: LIFA Infinity waterproof fabric with a PFC-free water repellent finish. It’s made from polypropylene fibres, which do not absorb moisture, and ensured it never ‘wet out’ on our tests. So, that’s weather sorted.

And when it comes to warmth, for us it was pretty much like wearing a sleeping bag. We weren’t cold even in sub-zero temperatures. It comes in men’s and women’s versions but is sized as an overlayering piece. Even then, the fit is generous, so you might want to size down (as we did).

Technical features are all present and correct – you get a two-way main zip with a full-length inner baffle. It has a soft chin guard at the top and a press stud at the bottom. The hood is big, cosy and helmet compatible. Lined hand pockets are fleecy and two inner pockets provide practical storage (one is zipped for security; the other is a big stretch mesh dump pocket for gloves). There’s also dual hem adjustment and elasticated, wrist-hugging cuffs to lock in maximum heat.

Be in no doubt this jacket is weighty and bulky. It weighs about a kilo, and even in its stuff sack, fills the bottom of a 40L winter pack. And the techy fabrics and fill means it is very expensive for a synthetic jacket.

Check out the women's version here

That hiking or running adage about being bold and starting cold is true but read out in full, it’s not quite so catchy. It goes something like: ‘Be bold, start cold, and you’ll soon heat up as you get moving. The problem with this is that winter mountain conditions can vary greatly and rapidly, and starting cold just might make you miserable’.

This is where we found Black Diamond’s First Light Stretch Hoody fills a much-needed niche. It’s much lighter than the big winter jackets here, and far, far more breathable. Yet, it carries enough insulation and weather resistance to be a fantastic put on and leave on layer.

Whether we layered it under a hardshell when the conditions were gnarly, or as the outer layer when they calmed the Black Diamond jacket kept us very comfortable.

Key to its success is its intention as a climbing and skiing jacket. Both of these activities demand highly breathable garments that allow unrestricted movement. Thanks to PrimaLoft Gold Active insulation, and stretchy 20D nylon fabric, the First Light Stretch Hoody excels in these areas.

The fabric is soft and cosy, yet impressively wind and water resistant. The fit is reasonably relaxed with underarm gussets, but the hem is quite short so coverage isn’t as good as some jackets here. However, the trade-off is that it’s ideal for technical routes and scrambles.

Check out the women's version here

Slim-fitting and lightweight, the Divide Fusion Stretch Jacket looks outgunned amongst present company. Indeed, we found it can’t offer the same level of outright warmth and protection as most of the heavier rivals recommended here. But it has its own, unique and very effective weaponry.

Being made to a slim shape, we found the Divide Fusion Stretch Jacket is the best for layering out of all the winter jackets we tested. And the athletic cut doesn’t inhibit freedom of movement because all the fabrics (20D Toray and wool side panels) used have generous four-way stretch. Breathability is superb, too.

This jacket is armed with intelligent features. For example, the DWR (called EMPEL) is not only PFC-free, but permanent, meaning it doesn’t require reproofing like most DWRs do. The 700-fill down is hydrophobic but also uses a novel, chemical-free treatment that outperforms the industry-standard approaches.

Something else in this jacket’s favour we noticed is that it doesn’t seem to suffer from down leakage like down jackets are invariably prone to. So, although quite expensive for the outright warmth it offers, the Divide Fusion Stretch Jacket is an amazing winter mid layer that avid winter hikers highly benefit from.

Check out the women's version here

Read our full Artilect Divide Fusion Stretch Jacket review here

This insulated jacket uses top-end Gore-Tex Infinium shell fabric and Sprayway’s ThermoSphere loose fibre synthetic fill, which is zoned, with 96g in the body, 55g in the sleeves, and 25g in the hood and collar. This provides warmth where you need it most whilst minimising overall weight and bulk.

The Grendel comes with a stuff sack and compresses nicely, fitting easily into a daypack. On test, it proved more than warm enough for cold winter hill days. It’s also completely windproof and very weather resistant.

The synthetic insulation still provides dependable warmth when wet. It’s worth noting that, as with a lot of Sprayway clothing, the fit is generous. We ended up sizing down. This gave us a nicely cut jacket that worked over or under a shell, making it a versatile all-purpose insulator.

Adjustable cuffs and dual hem drawcords lock in heat, as does the excellent hood. This has a wired peak and three-point adjustment. It just about works with a climbing helmet but seems better suited to winter hillwalking. Unusually, the hood rolls away with a Velcro tab. Some might find this superfluous, but we liked the feature. It stops the hood acting as a windsock when not in use, and creates a cosy, padded baffle around the back of the neck.

Other good features include a high collar that zips up above the chin, roomy and well positioned hand pockets, and inner and outer zipped chest pockets.

The price is high for a synthetic insulated jacket. At the moment, there’s no women’s version of the Grendel either – maybe next season?

Check out the women's version here

This is a light but warm baffled down ‘puffer’ from Jöttnar, the British brand with the Nordic name. It's been around for about a decade now and still seems to fly under the radar a bit. However, in our opinion, Jöttnar makes some of the best outdoor kit around.

The Fenrir has a 30-denier ripstop nylon shell, with stitch-through baffles stuffed with 850 fill power goose down. It’s also finished with a permanent water repellent treatment for improved resistance to moisture.

But the Fenrir uses synthetic insulation in the neck, hem and cuffs – all areas that tend to get damp. When combined with that hydrophobic down fill, it meant that on test, this jacket was far more versatile and weather-resistant than most down puffers. Though, we did notice its stitch-through baffle construction did lead to occasional cold spots.

It packs away into a very small stuff sack and offers impressive warmth for weight. We found there were lots of nice details too: zipped hand pockets and an internal chest pocket; anti-snag hem drawcords; stretch cuffs that fit easily over gloves and an elastic-bound hood with rear volume adjustment.

However, there were a few missing features such as a non-helmet compatible hood, and lacks a two-way main zip, which limits its suitability for more technical use.

But we think this jacket has a wonderful cut and fit. It’s an ideal extra layer for hillwalking or backpacking, being especially well suited for use at rest stops, summits and on chilly wild camps.

Check out the women's version here