Waterproof jackets and base layers are what people tend to grab first when putting together their hiking wardrobe. But the importance of a mid-layer cannot be overstated. It adds that depth and versatility to your layering system, just like adding Worcestershire sauce adds depth of flavour to a casserole.
Mid-layers vary a lot both in performance and design. They can range from a typical fleece or merino to a lightweight down jacket or thicker softshell. In this guide, you will learn what you need to look for in a mid-layer, plus we've recommended some of the best.
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What to look for in a mid layer
Breathability vs weatherproofing: While a good level of wind- and waterproofing is desirable in shell layers which form the outer face of your protection, for mid-layers it’s more important that they are breathable, allowing moisture from your sweat to escape without making you feel clammy or cold.
Quick-drying: Part of a mid layer’s ability to keep you comfortable is how quickly it dries. If it wicks your sweat rapidly but then holds on to it, you’ll soon become uncomfortable. Likewise, if you’re caught in a sudden downpour before you can get your waterproof on. A fast-drying mid-layer is essential.
Warmth: Mid-layers come in a variety of forms, from thin fleece to thicker insulated fabrics. Consider the time of year, the intensity of the activity, and your own tendencies to run hot or cold when deciding how warm you need your mid-layer to be.
Bulk: Because a mid-layer will be worn under a shell it’s important that it’s not too bulky. Warmer, more insulated mid-layers may feel overly restrictive once a snug-fitting shell is pulled on over the top.
Fit & stretch: A snug, close-fitting mid-layer will work better under outer layers but can feel restrictive unless the material has a good level of stretch. This is particularly important for more upper-body-intensive activities such as scrambling and climbing.
Venting with zips: Pull-over mid-layers may only have a short neck zip, while full jackets will undo all the way down allowing more warm air to escape if required.
Gilets: Unless you suffer from particularly cold arms or hands, a sleeveless mid-layer may be the best option. It will keep your body warm without increasing bulk within the arms of your shell layer.
The best mid-layers for hiking
1. Mountain Equipment Shroud Hooded Jacket
Trail Gear of the Year 2023 Winner
This crowd-pleasing piece is an exceptional insulation layer that has earned top-spot in the
Mammut Eigerjoch IN Hybrid Jacket
1. Mammut Eigerjoch IN Hybrid Jacket Men's
2. Mammut Eigerjoch IN Hybrid Jacket Women's
Pros: Stretchy, warm, comfortable, highly breathable
Cons: Trim fit, no hand pockets
This hybrid jacket is part of Mammut’s Eiger Extreme collection, the Swiss brand’s showcase range of technical performance layers. It employs the same body-mapped design as the Montane and 66° North jackets featured here but takes it to the next level in terms of technical fabrics.
Like Dynafit’s Mezzalama, it uses Polartec Alpha insulation for warmth, but in an unlined construction called Alpha Direct. This eliminates the mesh liner, saving weight and improving permeability and breathability. It’s a great fabric, providing the same soft, fast-wicking feel as high-loft fleece but without so much heat retention, ideal for high-output activity.
The shell fabric is Pertex Quantum Air with Diamond Fuse – basically, an even tougher type of ripstop nylon. Lastly, the underarm and back panels use stretch fabric for improved freedom of movement. It’s actually a blend of synthetic fleece, spandex and natural wool, which helps to resist odour and regulate body temperature. This ensures a body-skimming fit, but with great mobility. Generous arm length, stretch cuffs, and thumb loops make for even better coverage.
A zip neck and part-elasticated hem lock in further warmth. A full-length zip with inner stormflap and two zipped napoleon-style chest pockets complete the streamlined feature set, resulting in a highly impressive technical mid layer.
Verdict: Technically advanced hybrid jacket that’s superb for high energy activity in cold climes.
Salewa Agner Durastretch
Best softshell jacket
Pros: Fantastically comfortable, recycled fabric and PFC-free DWR, well positioned pockets
Cons: No Velcro wrist cuffs, not that warm, fit won’t suit everyone
On first impressions this jacket appears rather simplistic, with a minimalist style and only basic features. But, out on the hill, it transforms into a real gem – super-comfy, ultra-stretchy, wind-resistant, water-resistant, and with an athletic cut ideal for agile movement in the mountains.
Its recycled Durastretch fabric delivers decent breathability, and it's a jacket that copes fine in light showers (courtesy of the PFC-free DWR finish). The Agner provides a touch of warmth, but doesn't maximise warmth.
Features include a well-shaped hood, integrated collar, elasticated wrist cuffs, waist hem adjustment, patch pocket on the right sleeve, and two map-sized zippered hand pockets, which are positioned high to enable access while wearing a hipbelt. But the real USP is the stretchy fabric, which delivers first-rate freedom of movement and holds its shape well (the waist hem doesn’t lift, for example) during dynamic mountain antics.
The hood isn’t adjustable and doesn’t have a wired peak, and there’s no Velcro closure on the wrist cuffs. The athletic fit won’t suit all body shapes and it’s not the warmest option.
Verdict: Verdict A super-stretchy softshell with an athletic cut and minimalist design – but it won’t suit everyone.
Black Diamond Factor Hoody
Pros: Great fit and comfort , nice warmth-breathability balance, suitable for most seasons
Cons: Poor sustainability, no thumb loops
Like a lot of US brands, Black Diamond kit is sized generously, so you may want to drop down a size. Once we’d done that this proved a great-fitting layer, with a trim silhouette but plenty of length in the arms and body.
The fabric has good in-built stretch for first-rate freedom of movement, making this an ideal hoody for scrambling and mountaineering. The fabric is a smooth jersey knit, which means it slides easily underneath a shell or a windproof and doesn’t ruck up when you’re trying to pull on your waterproof just before the heavens open.
The soft microfleece inner offers good comfort levels, with vertical channels to aid breathability. This strikes a great balance since the heavier fabric offers increased warmth over lightweight gridded microfleece, without sacrificing too much breathability. That makes this a fleece you can wear all day as a winter mid-layer, using the full zip for venting if needed – as well as the chest and twin hand pockets since these are all mesh-backed to aid cooling. Pockets are placed high enough to avoid a rucksack hipbelt, and you also get a good hood. It doesn’t hug the face quite as closely as some, but there is a generous chin guard at the top of the zip to minimise irritation.
The sleeves lack thumb loops, but they are at least long enough and tight enough to cover the wrists. There’s a small amount of natural wool (2%) in the fabric blend, but no recycled fabrics.
Verdict: Great for tough winter adventures, this fleece finds an optimum balance between warmth and breathability. But it would benefit from significant sustainability improvements.
Patagonia Nano-Air Hoody
Best lightweight synthetic insulated jacket
Pros: Very comfortable, very breathable, surprisingly warm
Cons: Expensive, not the most durable
Patagonia's soft, stretchy Nano-Air Hoody is for you if you're seeking comfort and breathability. Predictably, it's a relatively slim fit, using Patagonia's FullRange insulation rather than fake plumage. It's certainly light when you wear it and supremely comfortable but it doesn't pack down like the brand's Nano Puff, for example.
There are plenty of features we like. The chest pocket is a nice touch; the comfy, removable hood helps add that bit of extra warmth without adding much bulk; and it does still have a stuff sack to keep it compact. Climbers will certainly appreciate the pockets positioned high enough to still use while wearing a harness.
In line with Patagonia's ethos, the Nano-Air uses mostly (87%) recycled polyester for the shell and the insulation is 40% recycled. Like the Nano Puff, it's not a cheap garment but then, you are getting a lot in return.
Verdict: Very comfortable and breathable - ideal for high-output hiking sessions. But it's rather expensive.
Rab Infinity Microlight
Best lightweight down jacket
1. Rab Infinity Microlight Jacket Men's
2. Rab Infinity Microlight Jacket Women's
Pros: High weather protection, lightweight, sustainable
Cons: Features are overkill for some
If there is such a thing as a modern classic in outdoor kit, Rab’s Microlight jackets have a good claim to the title. We reckon the Infinity Microlight is the best one yet, featuring a Gore-Tex Infinium face fabric and 700 fill power recycled hydrophobic down insulation. It’s a consummate all-rounder for the hills and mountains, being warm, packable, and more weatherproof than most down puffers.
Lightness is obviously important here, since we're not talking about a full-bore insulated winter jacket. The Infinity Microlight weighs just 450g (approx), offering high levels of breathability and warmth from its slim design.
Whether for alpine adventures or speedy hikes, the Infinity Microlight is a top jacket. It impressed us so much it won our 2022 Gear of the Year 'Best insulated jacket' category.
Verdict: This is a warm, cosy and well-cut puffer that won’t collapse into a soggy mess even if you need to stick it on in clag or light drizzle.