Best synthetic insulated jackets 2024 for hills and mountains

One word to capture the essence of this jacket: versatile. Not compromised – versatile. Icelandic brand 66° North knows a thing or two about insulation and has applied some impressive know-how into this high performing, yet surprisingly lightweight jacket.

The main fabric is mildly stretchy nylon and feels soft like your favourite home hoody. It’s therefore comfy and snug but out in the hills, it’s amazing. The outer material batters away wind and a reasonable amount of rain.

We found the synthetic insulation is breathable and moderately warm (helped significantly by the weatherproof outer). You can wear it as an outer layer in cooler conditions or as a mid layer underneath a hardshell if you’re braving winter mountains.

There are a trio of zipped external pockets – two of which are handwarmer pockets, and a third on the chest. We liked the elasticated cuffs and extremely smooth one-way main zip.

There’s very little to fault with the Hengill. It’s obviously quite pricey, but its versatility addresses that somewhat, and 66° North offers repairs on all its gear (plus, it’s a certified B Corp). And perhaps you’d want something with more insulation if you’re after a purely hardcore winter jacket.

Check out the women's version here

According to its designers, this is Alpkit’s most sustainable jacket to date. The construction is fairly minimalist, with pretty much everything but the zips being 100% recycled polyester.

That includes the filling, which is ‘Primaloft Silver Eco’, an airy yet impressively warm synthetic fill which Alpkit also use in their sleeping bags. Of course, there isn’t as much fill here – a density of 60gsm is good for lightweight year-round warmth.

The Heiko is impressively lightweight, at 344g (men’s M). And combined with the lofty fill and soft, almost silky feeling of the interior, it’s the kind of jacket that you can forget you’re wearing.

That said, the fit isn’t as tailored as other picks here. You’ll want to make sure you’re buying the correct size, as this jacket looked slightly boxy on our tester, but an elastic drawcord around the hip means you’ll still get a tight seal if the wind is really whipping.

The inner and outer are both 100% polyester, with the outer treated with a PFC-free DWR for water repellency. You’ll certainly get by in a drizzle, and the thinness of this piece makes it ideal for layering under a waterproof shell.

Check out the women's version here

Rough and ready for snow-covered mountain adventures, the Xenair Alpine jacket from Rab is highly protective, being filled with PrimaLoft® Gold Active+ synthetic insulation.

This fill is far more effective than lighter, thinner options. It’s made from 55% recycled material and is spread throughout the jacket at two different densities. Under the arms and up the spinal column, you’ll get a density of 100gsm, while the rest of the jacket is insulated at 133gsm, which is certainly noticeable. This jacket feels especially plush around the chest and shoulders, as well as the waist, which can be tightened.

The 20 denier Pertex Quantum Air outer feels durable and yet more breathable than many other Pertex fabrics. With a jacket this thick, breathability is crucial, and the Xenair’s primary aim is to give you the option to either cinch up tight or allow plenty of airflow throughout.

There’s also no shortage of pockets in the Xenair, with two concealed chest pockets for more storage on top of the spacious hand pockets, all four of which are sealed with the secure YKK zips.

And finally, we really like the elastic patch on the wrist, which can be loosened and tightened for use with gloves or to ensure no cold gets in. The Xenair feels nice and secure, so it gets two big thumbs up from us.

Check out the women's version here

The Montane Fireball Lite Hooded Insulated Jacket is specifically designed with high-intensity outdoor pursuits in mind, such as hiking, climbing, and fastpacking.

This jacket showcases a smart panelled design, with the main body being constructed from Montane's Featherlite Air nylon, a fabric that boasts stretchiness and excellent air permeability. Furthermore, it comes treated with a DWR (Durable Water Repellent) finish and is filled with 40g/m2 recycled polyester insulation, which results in impressive breathability and unrestricted movement. The fleece sides and underarm panels are thoughtfully made from a cozy and flexible Thermo Grid material.

The Fireball Lite Hooded Jacket is equipped with two convenient front zip pockets, providing enough space to stash essentials like your phone and small snacks. The slim hood can fit comfortably under a bike helmet if necessary.

It's important to note that this jacket doesn't offer much in terms of windproofing or outright warmth, which we found makes it a bit of a specialist as an active insulating layer in nippy rather than winter conditions.

When it comes to sizing, if you're looking for a regular fit, a women's UK8 size fits true to size. There's plenty of room beneath it for layering, and it also offers a bit of extra length in the body.

Check out the men's version here

This jacket utilises advanced materials and clever design to excel in high-intensity activities in cold conditions. It clearly signals its suitability for active use through various features. The chosen fabrics prioritise breathability, complemented by body-mapped PrimaLoft Gold Active insulation.

As expected, the adjustable hood is compatible with helmets, and as a bonus for those seeking a portable option, the First Light Stretch Hoody can be conveniently packed into its internal mesh pocket. We liked the articulated sleeves as well, which, along with the stretchy fabric, give you superb freedom of movement.

Our testing revealed that this jacket's outer fabric is impressively wind and water resistant. Despite its lightweight 20D construction, it's surprisingly durable too.

There are a lot of similarities between this and the 66° North Hengill. However, we found the 66° North Hengill is ever so slightly better as an all-rounder, where the First Light Stretch is best for more specialist activities like climbing where freedom of movement is really important.

Check out the women's version here

For those seeking a lightweight insulating layer to enhance their casual hillwalks and hikes, infusing a touch of style into the equation is always a welcome bonus. In our assessment, the Teca Cálido jacket from Cotopaxi, a brand hailing from Utah, does the job perfectly.

Our testing revealed several compelling reasons why this jacket stands out as the perfect synthetic insulated jacket for peak-to-pub walks. Its lightweight insulation performs admirably in cooler conditions during relaxed activities but can become a tad warm during more strenuous endeavors.

Furthermore, the Teca Cálido boasts a plethora of practical pockets, including two-way handwarmer pockets, and its reversible design provides you with not just one chic jacket, but two.

In terms of sustainability, this jacket earns its stripes. The outer polyester fabric is repurposed from excess material from other companies' production runs, and its insulation is also recycled. While it may not qualify as PFC/PFAS-free, this is primarily due to the use of repurposed materials, which originate from sources beyond Cotopaxi's control. It's produced in a Fair Trade Certified factory and Cotopaxi is also a certified B Corp.

Adding to its appeal, the Teca Cálido offers excellent value, priced at least £100 lower than other, more technically advanced lightweight insulated jackets on the market.

Check out the men's version here

You reckon this looks like a ski jacket? You’re right, it is. Well, write it off then because it’s obviously no good for hiking. Not exactly.

At about 900g, it’s heavier than the other options here but it’s still not that heavy. We found that The North Face Freedom Insulated Jacket is a dependable all-round jacket for mid-winter adventures in the snow – be it walking or snow sports.

Unlike the others here, the Freedom Insulated Jacket is properly waterproof, employing a durable, PFC-free, 2-layer construction. The recycled insulation is a bit lighter in the sleeves than in the torso, which helps with freedom of movement. We found it doesn’t have the breathability of the other jackets here, but for something like this it’s pretty good, and has pit zips to boost it.

Given this jacket is designed for snow sports, it has all the features for it, including a snow skirt, helmet-compatible hood, large pockets (including one on the sleeve housing a goggle wipe), double stormflaps, glove-friendly zip pullers, and Velcro cuffs. Most of these features are useful for snowy hikes too.

This jacket will work for plenty of people. No, it’s not a bona fide hiking jacket but it doesn’t matter, it can be used as such when it's really cold, and for skiing. Given the high cost of jackets, one that is versatile is always worth considering.

Check out the women's version here

This is a unique pick for several reasons. The quarter length zip makes this is the only over-the-head jacket in our list, the synthetic insulation is lightweight and works well in wet conditions, but most importantly, it’s got a giant kangaroo pouch on the front.

The second we put this jacket on, it was all about investigating this big central pocket. It’s a fluffy cavern accessible via what look like two separate hand pockets. The fact that they join in the centre is actually great for keeping your fingers toasty on cold outings.

In addition, a huge cross-body zip reveals yet more storage in the stomach area. An extra large pouch constructed from water-resistant Flylite Ultra fabric, which sits under the durable Cordura which makes up most of the jacket.

This zip tucks away under a flap but doesn’t look to be particularly waterproof. It seems the angle here is fast access to a camera or headtorch, or any other essentials you want to keep within grabbing range. We liked it for energy bars, but at this size, the possibilities are endless (provided you don’t mind looking a little chunky around the midsection).

Be mindful though, it already weighs 520g, so loading up this jacket might make for a bit of extra strain.