The key to staying warm in the great outdoors? Think like an onion and get layering. The best way to trap in warmth without overheating when you’re out exploring in colder weather is to wear a base layer next to the skin, a waterproof shell jacket and between them, the hero piece – a great mid layer.
Mid layers come in different materials and thicknesses, but the best ones will keep you cosy whether you’re camping, hiking, skiing or just walking the dog on a bitterly cold morning.
We recommend choosing either fleece or insulated mid layers, and we’ve included both in our round-up, all of which we put through their paces in the elements.
Insulated jackets, which are stuffed with either animal down or a synthetic insulation, are brilliant at keeping you warm without weighing you down.
Synthetic fill tends to be lighter but can feel bulkier than animal down – it also performs better when wet. Animal down is very warm yet lightweight to wear, usually offering a better warmth-to-weight ratio than synthetic insulation but doesn’t work when wet. Animal-sourced down can also be unethically harvested from ducks and geese – so it’s best to avoid cheap down jackets and pick a good quality one from a brand that offers full information on how and where their down is sourced. Or simply avoid this issue by choosing a jacket stuffed with synthetic insulation instead.
Fleeces are made from synthetic (and often recycled) fabrics and are highly breathable, machine-washable, and quick-drying. Like merino wool and other thinner mid layers, they tend to be less bulky but less warming than insulated models.
Mid layers aren’t usually waterproof – you can wear warmer mid layers as a standalone jacket on clear, cold days but it’s best to pop a waterproof shell on top when venturing out into rain and snow. That said, some of the latest mid layers we tested are water resistant, meaning they’ll put up with lighter rainfall if you do get caught out in the elements.
Whatever model of mid layer you go for, a good one should ideally have zipped pockets for stashing your essentials and a high neck for helping to protect your face from the wind. A hood is also useful – ideally one that’s adjustable and can be drawn snugly around your face.
Lighter insulated jackets often pack down into a stuff sack or into one of their own pockets, which is great for popping your jacket in your backpack on the go. If you want to warm your core but keep your arms unencumbered, we recommend picking an insulated gilet.
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Fjällräven expedition pack down hoodie jacket
Warning – you’re never going to want to take off Fjällräven’s latest and greatest down jacket. After testing it on multiple autumn hikes we have nothing but good things to say about this smart and super-warm mid layer. Inspired by Fjällräven’s first down jacket, designed back in 1974, it combines classic looks with ethically traced down and a recycled nylon outer material. There’s a host of thoughtful design features here – from an adjustable hood to a high neck lined with soft fleece, deep, well-placed inner and outer zipped pockets and a hip-skimming length, which offers extra warmth. The hoodie fits easily under a waterproof jacket but might be too warm for the mildest autumn days – this is one to crack out when the mercury drops.
Canada Goose hybridge lite down vest
A down gilet is a versatile bit of outdoor clothing for winter, keeping your torso toasty while leaving your arms to move freely. Canadian brand Canada Goose is best known for its enormous down parkas, but we’d argue that this hybridge gilet, lite by name and light by nature, is the brand’s hero piece for this season. Slip it over a base layer or under a fleece and you’ll barely realise you’re wearing it – until it starts to warm your core up a treat. We love the stretchy fabric side panels, which give the perfect fit, and comfortable high neck. The oil slick-shiny looks (and the eyewatering price point) might not be to everyone’s taste, however.
Berghaus tephra stretch reflect down jacket
Designed with the cold in mind, Berghaus’s tephra stretch jacket is packed with technology that will keep the chill at bay. An inner lining traps body heat, and water-repellent hydrodown offers great warmth even if it does get fully wet. The sides of the jacket are made of stretchy fabric rather than down, helping to hug the jacket to your body. When testing this mid layer on treks we found the panels a big help for keeping it in position under a waterproof or when worn with a rucksack, although the thinner fabric panels are inevitable colder. Our only concern is that the outer material seems rather thin and easy to snag, so just make sure you keep it away from sharp edges.
Jottnar fenrir down jacket
Jottnar’s technically excellent outer layers are designed with mountaineers and backcountry skiers in mind, hence the hefty price tags – but we wore this absolutely everywhere last winter as both a mid layer and a warm outer layer, making spending almost £300 on a jacket suddenly seem a lot more sensible. The 2020 version is supremely comfortable, and instantly warms your core when you pull it on – this was the warmest down jacket we tested overall. Despite feeling on the bulkier side, it still sits nicely under a waterproof shell and is compact enough to stuff into a small sack for easy transportation. Other highlights include the roomy zipped pockets, a handy inner pocket and a snug hood. This is well worth the investment if you’re out in cold conditions regularly.
Montane Phoenix stretch down jacket
Montane’s Phoenix proved to be a high performer on test, balancing good warmth and light weight despite using synthetic insulation rather than down. Weighing in at just 380g, this traps in heat effectively thanks to recycled inner stuffing. This is another insulated jacket that combines warm down with form-fitting stretchy fabric side panels, but we found the fleecy material used here still offers some warmth around the torso. Similarly to the Berghaus tephra, these panels make the jacket fit well and stay put if you’re moving fast, such as when climbing or hiking, or if you’re wearing a rucksack. A good choice if you’re getting active and want to avoid wearing animal down.
Giesswein svenja jacket
Dreaming of a warm, eye-catching mid layer that you can wear pretty much anywhere? Meet Giesswein’s smart svenja. Made from 100 per cent merino wool, which is naturally antibacterial and wicks sweat away, as well as feeling luxuriously soft to wear, this breathable zipped mid layer is ideal fast-paced adventures where you’re likely to get hot such as hiking and backpacking, and for multi-day trips where you’ll be wearing the same layers again and again without a washing machine in sight. On test we liked the cosy hood and high neck, which add welcome warmth and layer up well under a waterproof. Multiple jewel toned versions of the svenja are also available, as well as a gilet version, the Stella (Giesswein, £134).
Helly Hansen odin stretch insulated jacket
Another hoody-style mid layer that uses synthetic insulation and skips the bulky quilting of most down jackets. The real standout feature of this Helly Hansen jacket is comfort. Nicely articulated and form-fitting without being restrictive, this jacket has a comfy stretchy finish that was lacking in most of the other styles we tested, making it ideal for all day wear when on longer adventures, such as trekking or ski touring. We also liked how breathable it proved to be on test, wicking away sweat in seconds. It is slightly bulky, though, and it doesn’t pack down small enough to be very portable.
Salomon outline down hoodie jacket
Combining impressive warmth with a true featherweight of 304g, the outline down is cleverly packed with goose down around the torso and synthetic insulation in areas that might get wet, such as the hood and shoulders. The result is a mid layer that keeps you both cosy and dry by combining the best of both insulating worlds. That said, it is too warm and not breathable enough to work when you’re really working up a sweat, or on mild, sunny winter days. The ripstop fabric is tough enough to last for years of adventuring, but we’d recommend picking one of the darker hued colourways, as the pastel blue version will show dirt quickly.
Sherpa rolpa jacket
Our top pick of the fleeces is this cosy and affordable jacket from Sherpa. A double-sided fleece that feels cosy and tactile both inside and out. It’s the perfect fleece for layering up, and we love its muted colourways and Nepali-influenced colourful trim. Go a size up when ordering this snug jacket – or if you prefer a roomier, boxy-cut to your fleece as opposed to slim-fitting female designs, we recommend choosing the men’s version of the rolpa, also £50. Whichever incarnation you pick, the rolpa is an ethical way to splash your cash, as proceeds from each sale help provide education and resources for the children of Nepal.
Nobis Lily down gilet
Looking for a little bit of luxury to stave off this season’s chill? Nobis’s sleek, form-fitting Lily vest might have your name on it. Nobis, the brainchild of one of the founders of Canada Goose, reckon its down pieces are “perfect for the tube as well as the tundra”, and we’d have to agree. The Lily may look pared-down and simple, but this gilet packs a performance punch. Stuffed with seriously warm duck down sourced from Canada and produced as a by-product of the poultry industry, the vest provides a quick hit of warmth and is also waterproof and windproof, but still highly breathable – ideal for changeable conditions. Owing to popular demand, if this is out of stock in your size be sure to sign up to the email notification for when it’s back.
Columbia alpine crux down jacket
This rather futuristic looking jacket uses Columbia’s omni-heat reflective inner material to keep you cosy. Comprised of thousands of little silver dots, this clever fabric traps heat quickly and efficiently and reflects it back to your body. A nicely cut high neck, snug hood and water-resistant outer material make this a great down jacket for use in foul weather as well as fair. We also liked the adjustable hem and deep pockets on test. The only downside to its tech-savvy construction is that the inner material feels rather plastic-like against the skin, and the jacket can look a tad on the tech side for more casual use. It fits slim – order a size up if you want to wear more than a base layer below it.
Finisterre nimbus insulated jacket
Finisterre’s Cornish designed, ethically made outdoor pieces always stand out for good looks and long-lasting quality. The brand’s nimbus jacket is our top pick if you’re after a high-performing synthetic insulated jacket with none of the ethical worries of down. It feels light to wear and is cut to move as you do – you’ll barely notice it’s on – and is a great mid weight, at 400g, that works well worn alone on autumn days or layered under a shell come winter. The matte finish and this season’s handsome rust red and powder blue colourways mean that this a really versatile choice for daily use, as does the fact it packs down into its own pocket.
Montane featherlite down jacket
Deserving of its feathery name with a light weight of 340g, Montane’s featherlite feels barely there when you slip it on, but it provides a welcome hit of heat from its fill of responsibly sourced duck down. On test we found the recycled nylon outer material to be tougher than other easily ripped mid layers. It’s also waterproof enough to withstand sudden rainfall – you can tell this jacket was designed with climbers and mountaineers in mind. The hood, which can be stored away and has a stiffened peak to protect from weather, is designed to fit under a climbing helmet and is a stand-out feature. A great choice for those who are frequently mountain bound.
Keela talus insulated jacket
We love the subtle look of this hooded talus, which is insulated with synthetic insulation (primaloft gold) but doesn’t have the Michelin Man-style that most down mid layers have. The use of primaloft gold insulation, which is effective even if wet, combined with a windproof outer material means this is ideal for use in environments that are open to the elements. The jacket will also still trap in some heat even if you do get caught in a storm. If you’re looking for a mid layer that can work as an outer jacket in most conditions, this is a great pick. While currently out of stock, Keela promises it’ll be back very soon – keep your eyes peeled.
Jack Wolfskin JWP down jacket
Part of Jack Wolfskin's well-named pack and go collection, the barely-there JWP is the lightest down jacket we tested at just 240g, yet it still offers impressive warmth and is windproof enough to keep that warmth trapped inside in adverse weather. On test, we liked the no-fuss simplicity of this mid layer, which stows away neatly into a carry pouch. The light weight and packability make this a great choice for trail runners, bike packers and skiers who value kit that doesn't weigh them down on the go.
The verdict: Women’s mid layers
Make sure you’re kitted out for the wet weather, read our review of the best women’s waterproof jacket that will get you through wind and rain
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