The Best Midlayers of 2026

The R1 has a storied history in the Patagonia lineage, and another sibling has been added to the set: the Patagonia R1 Thermal Full-Zip Hoody ($219). This ‘thermal’ cut aims to be the warmest of the bunch, and having worn all four different styles, we can confirm that it nails the effort.

The main differences between the Thermal R1 and the rest of the fleeces include a tight-knit face fabric that cuts through the wind and a grid fleece arranged in a much closer-spaced configuration to really bump up the BTUs. We’ve used this piece as an active insulation layer while climbing 10,000-foot volcanoes in the Pacific Northwest, and it has enough warmth to get us to the summit and back.

Besides the warmer fleece, we found the cut to be typical of Patagonia (a bit boxy in the torso but well-fitting), with sleeves at just the right length for tucking into the thumb loops from time to time. The hood can be run underneath a helmet, and you also get a second chest pocket in this R1 — very slick.

At higher outputs, the R1 Thermal will hit a breaking point where it’s just too toasty, which is when we reach for something with a looser weave like The North Face FUTUREFLEECE or R1 Air. The wind will cut through both of these midlayers, but if it’s just not that cold ambiently (or you’re pumping out the heat), they can balance the scale well.

You also won’t quite get as much static warmth out of the R1 Thermal as you will with a synthetic puffy like the Arc’teryx Proton or Patagonia Nano Puff, but the benefit of going with a slightly thicker fleece is that your insulation jacket can be lighter. For most of our winter layering systems, this fleece fits in perfectly.

A good facsimile to the R1 Thermal — for a good bit less — the REI Co-op Flash Hyperstretch Fleece Jacket ($100) checks most of the boxes we’re looking for in a midlayer. Warm enough, breathable when you need it, and stretchy to move with you. For less than a Benjamin, the Flash Hyperstretch does it all on the cheap.

Unlike the R1, the Flash Hyperstretch adds a few hand-warming pockets, which makes it better suited as an outer-facing layer. The longer torso length and drawcord cinch at the hem also aid in this effort, meaning you won’t have to rely on another jacket to keep errant breezes at bay.

The built-in stretch is also a notch above other fleeces we’ve tested, and that 11% spandex in the weave is put to good work when reaching high overhead. Unfortunately the budget cuts are apparent when you do this, as there are no thumbholes in the Hyperstretch. A small price to pay, we’d argue, as the fleece leans a bit more casual, and the absence makes sense here.

The hood, we found, is a bit too accommodating — almost like a sweatshirt hood, and won’t be quite as sportif as pieces like the FUTUREFLEECE from The North Face or NW Alpine Black Spider Hoody. Still, it’s forgiven for the ‘all-around’ bent on the Flash Hyperstretch. We enjoy wearing this jacket everywhere from bumping around town to winter runs, and for the money, that’s impressive versatility.

An entire sub-genre of loose-knit fleeces has sprung up in recent years, with notable tech in the form of Polartec Alpha Direct. The Octayarn fleece used in The North Face FUTUREFLEECE Full-Zip Hoodie ($190) is another take on the uber-breathable fleece, and when pushed to the limit on high-output ski tours or runs this winter, we found it well made the grade.

The FUTUREFLEECE fits more snugly than many fleeces, which helps to retain your hard-earned warmth between the uniquely bundled piles of yarn. The spaces between these bundles are quite thin, and allow for more air transfer when you really need to vent heat. While huffing up skin tracks in Colorado this spring, we found this hoodie to be the perfect weight.

Side-by-side, we found that the Octa fleece felt sturdier than Alpha Direct pieces, with an ultrathin outer face that helped keep the FUTUREFLEECE from being snagged on branches. All loose-knit fleeces are going to feel a bit fragile, but with the fleece yarns facing the interior of the jacket, there’s a good bit less to get caught on.

This fleece’s features are otherwise light, with a single chest pocket taking up slim real estate and thumb loops on the sleeves. The Summit Series from The North Face is all about high-alpine efficiency, so no love is lost here from us. Still, if a few dialed chest pockets are on your wish list, the Patagonia R1 Thermal is ready for action.

If you’re after a more summer-weight active fleece, consider the Senchi Alpha 90 Hoodie or Mountain Hardwear AirMesh Hoodie — both lighter weaves that work great at a hiking pace. For a wider range of conditions, however, the FUTUREFLEECE is our pick.

While the Atom line gets all the glory, we think that the Arc’teryx Proton Jacket ($350) is a slightly better synthetic midlayer from the brand. Styled as a more mountain-forward piece, the Proton is a bit warmer, uses a nicer synthetic fill, and cuts through the cold wind better. For a synthetic puffy, it’s tough to do better than this.

We’ve worn our Proton for more than 5 years now of constant use, and while it’s packed out some, it’s still going strong. The only other wear we’ve noticed has been the chest pocket zipper giving up the ghost and the logo wearing away. The price is undeniable here, but it pays out dividends in durability.

The 80 gsm PrimaLoft Gold used throughout the Proton makes it a notch warmer than the standard Atom (which uses 60 gsm), and compared to quilted synthetic jackets like the Patagonia Nano Puff, we tend to prefer sheet-style synthetic pieces like the Proton, as they retain more warmth without the losses associated with stitch lines.

Unlike the Atom (which uses underarm fleece panels to dump moisture), the Proton uses a more breathable Fortius Air 20 face fabric material to remain breathable. We found that in truly cold winds, the fleece panels on the Atom would let too much breeze through, while the Proton lets in just enough.

Ideal as a static warmth piece for shoulder season endeavors — or even an active piece for cold alpine climbing — the Proton has a dedicated spot in our closets.

Another midlayer from the popular R1 family, the Patagonia R1 Air ($189) sits at the other side of the spectrum compared to our top pick and is the most breathable of the bunch. This airy fleece isn’t as free-flowing as the North Face FUTUREFLEECE, but we found it to be a more well-rounded layer ideal for warmer weather.

The R1 Air is similar to most grid fleeces except that it isn’t laid out in a grid — it zig-zags. These passages open up air to move through the layer without having to pass through much face fabric first, making the Air best for quicker-paced activities. We tested the Air everywhere, from elevation-heavy hikes in the Sierra to romping up perfect granite in Washington State, and it impressed across the board.

While the FUTUREFLEECE only has a single external chest pocket, the R1 Air hosts three, two of which are hand-warming pockets that we enjoyed. The chest pocket is pretty low-profile, and we found it ideal for stashing small items like chapstick or a quick snack.

In terms of fit, the R1 Air sticks close to you, and while climbing, we found it fit well under a harness and had good mobility when reaching overhead. The hood is the same design as the R1 Thermal and is a snug scuba-style cover that can be run underneath a helmet. This does mean that it isn’t as casual to wear around (look to the REI Flash Hyperstretch for a sweatshirt-style hood), but when you want the warmth, it’s got it to give.

Like most other super breathable midlayers, stiff winds will be an issue, and we recommend stacking a light wind shirt over top whenever the breeze picks up. But if you want a breathable midlayer that you’d still wear out to coffee, the R1 Air is a contender.

Now the standard uniform of thru-hikers across the country, the Senchi A90 Half-Zip Hoodie ($115) is an ultralight fleece that excels as a wear-it-all-day piece. Made from Polartec Alpha Direct 90, the A90 weighs between 4 and 6 ounces and breathes so well that we can keep it on while hiking at a decent clip.

A simple half-zip hooded design keeps the A90 low-bulk and easy to layer over. The Alpha Direct fabric is incredibly airy and breathable, with the pile fleece facing outward. The chest zipper is just enough to blow off some excess steam when working hard on a climb, and the thumb holes are perfectly placed to cover the hands with the sleeves.

The North Face FUTUREFLEECE is a comparable mainstream fleece with the yarn facing inwards and a harder face material. This makes the piece more durable, but also a bit warmer, making it better for colder weather. For wearing all day in cool conditions or sleeping in, the A90 is the better choice. 

The downside to the Senchi is attempting to get your hands on one. Like the uber-popular Melanzana fleeces, Senchi releases these midlayers in drops due to demand. We’ve also seen some durability issues with the delicate fabric, having ripped the sleeve of one of our earlier versions. Nothing a little needle and thread can’t fix, but it is a concern for those putting serious miles on these fleeces.

If you can snag one, the A90 Half-Zip Hoodie won’t disappoint. It perfectly complements a light down jacket in a backpacker’s loadout, acting as active warmth and adding some sleeping comfort to cold nights. 

Over the years, the Patagonia Nano Puff ($229) has garnered nothing but praise. The size, style, and color options are varied, the insulation is warm, and the jacket itself is packable and lightweight. And unlike with down puffy jackets, you won’t be leaving feathers in your wake.

There’s a reason the Nano Puff has been in stores since 2010. And while it’s always been a bestseller and a staple in our wardrobe, there have been improvements, such as the 100% post-consumer recycled insulation. Like a good cheese, you could say the Nano Puff only gets better with age.

The lightweight and synthetic-insulated Nano Puff is windproof and water-repellent, boasts a standard 60 gsm insulation, adjusts at the hem to seal in warmth, and has two zippered hand pockets. Compared to other midlayers we’ve worn, we’d say the warmth here is less than 80 gsm synth jackets like the Arc’teryx Proton, but warmer than grid fleeces like the Patagonia R1 or REI Flash Hyperstretch. In practice, that’s a great middle-ground.

We’ve used the Nano Puff extensively for summertime forays on its own, and during shoulder season and winter exploits when worn beneath a shell. Going with the hoodless jacket version means you’re saving space in your bag for jackets with them, and like the REI Flash Hyperstretch, the Nano Puff is also a bit more casual-conscious. We think this jacket looks great styled up for a cool night out on the town, or covered in patches — whatever floats your boat.

The Nano Puff can’t be talked about without mentioning Patagonia’s other primo synthetic midlayer, the Nano Air, which is rightfully popular as well. We think the Nano Air works better as a stretchy midlayer with a bit more warmth, but doesn’t look as chic as the Nano Puff. If you’re splitting time between the wilds and the sidewalks, we think this is the better layer.

The Arc’teryx Atom SL Hoody ($280) has become one of our top-choice trail running or cycling layers for quick-paced efforts in cold conditions. The lightest member of the Atom line, this hoody dumps excess heat when you’re working up a sweat, and it packs away compactly.

This is just about the thinnest synthetic midlayer you’ll find out there, and it’s only insulated in the torso, meaning it’s more suited to warmer conditions (or when you’re providing your own warmth). The arms and hood are uninsulated, with Octa fleece side panels and underarms to keep moisture moving.

The material tech doesn’t end there, either. Inside the sleeves is a thin mesh lining that helps wick away sweat, and the whole jacket is treated with a PFC-free DWR finish to fend off light precip. Don’t expect much from this (our testing proved as such), but it is helpful if you’re caught out without a shell.

Compared to The North Face FUTUREFLEECE, the Atom SL certainly turns away breezes better and works more like a standalone jacket than the insulation-only fleece. The Outdoor Research Deviator is fairly similar and is a cheaper alternative for similar outdoor uses.

Ultimately, the price keeps the Atom SL from ranking higher in our midlayer lineup, as $280 is pretty steep for a layer that doesn’t provide much warmth on its own. Instead, we think the high-caliber materials make it a grail piece: If you want the nicest thin synthetic layer out there, this is it.

The original Nano-Air has been an all-time mega hit for Patagonia. The brand released a more breathable hybrid fleece with Nano Air Ultralight Hybrid, and now the Nano-Air Ultralight Hoody ($249) aims to hit a sweet spot between warmth and breathability. If you’re a fan of the original, have the cash to burn, and love tweaking your layering system to perfection, you’ll love this lightweight jacket.

The big difference between the ultralight and the original Nano Air is that there’s simply less insulation. While the regular Nano-Air packs in 60 grams of breathable Fullrange insulation, the Ultralight version pares it down to 20 grams, has a thin layer of Patagonia’s Capilene material in the forearms, and eschews the hand warmer pockets. The Ultralight is almost half the weight of the original.

This is an excellent layer for ski touring, especially on cold days when the wind is calm. You can climb fast and get warm without needing to take off the jacket or getting too sweaty. You’ll need to throw on a puffy if you stop for long or hang out at the summit; the jacket is not warm enough on its own to stand around in on a good ski day. While there aren’t any handwarmer pockets, the chest pocket is large enough to hold a phone or a few energy bars.

The Nano-Air Ultralight is also a great climbing piece. It has an athletic cut and fits well under a harness, with plenty of stretch for a full range of movement. It easily stuffs into its chest pocket and can be clipped to your harness. At 60 degrees in the shade, sport climbing felt near perfect with the Nano-Air Ultralight on.

Our tester has a knack for destroying clothing, and the Nano-Air Ultralight received a small tear on the sleeve during his third time climbing in it. It’s tougher than Patagonia’s Micropuff Hoody (which lasted 3 pitches before it was in tatters). This is something to consider if you are particularly rough on your gear. The Arc’teryx Proton is a similar breathable midlayer, and while it’s not as breathable as the Nano-Air, its a whole lot tougher and quite a bit warmer.

While most synthetic midlayers are in a race to the bottom, the Himali Ascent Stretch Hoodie ($250) fills the hole left in our hearts by the Arc’teryx Atom AR with a thick 100g PrimaLoft Gold fill. For cold and wet action outdoors, this midlayer wins.

This is certainly a winter or mountaineering midlayer, and the warmth it provides is ample. We could wear only this layer in below-freezing temperatures and still be quite comfortable. The 100g PrimaLoft is spread over the entirety of the hoodie, and an athletic cut fits snugly to limit air space.

The trim and feature set is angled at climbers, with a helmet-compatible hood and 4-way stretch fabric that has a surprising amount of give to it. Even with the athletic fit, we could pull overhead reaches with ease. A two-way front zipper would have sealed the deal here, but the Ascent only hosts a one-way version.

At $250, the Ascent Stretch undercuts several similar midlayers, including the Arc’teryx Proton ($350), and is warmer than that midlayer. We’ve also got confidence in Himali as a brand, as its Monsoon hardshell jacket recently impressed us greatly compared to other high-end mountaineering jackets.

The packed size of the Ascent isn’t astounding (we can get it down to about the size of a football), but it does stash away well into the included stuff sack. Interestingly, this stuff sack is sewn into the hand pocket of the hoodie — something we tried to use, then opted to snip out and use solo.

The exterior fabric of the Ascent Stretch is treated with a DWR coating to shed light precipitation, but due to its stretchy nature, it doesn’t last long in real rain. Something like the Patagonia DAS Light Hoody, with its nylon shell, will be more weatherproof but not as warm. Overall, we think the Ascent Stretch fills a hole in our closets well.

The Mountain Hardwear Kor Pullover ($225) is a “techy take on your favorite sweatshirt,” reports Bergen Tjossem after using it as a midlayer for mountaineering and skiing in the French Alps. This hoodless crew certainly looks the part and uses some stellar materials to balance warmth and breathability.

Made from Pertex Quantum Air and PrimaLoft Gold Active, the Kor gets the full treatment of high-performance tech to create a versatile layer. The insulation is mapped out to cover the front of the torso and remove it from sweaty areas on the back and beneath the arms, and the Pertex material is alternatively coated and uncoated to enhance wind resistance where you want it.

This hybrid cut means the Kor Pullover works best for active pursuits where you’re taking the brunt of the weather straight on, and it isn’t the most breathable for activities like running. Compared side by side with the Black Diamond First Light Hybrid, which uses the same PrimaLoft Gold Active, that layer ventilated better, due to the non-windproof face fabric.

The Kor Pullover, instead, is a bit more casual and slower-paced, with a look that can easily transition from outdoors to indoors. The sleeves and hem aren’t cinchable but instead sport large elastic bands to keep them snug. The layer will still stash into its own pocket, however, and gets down to about the size of two fists.

The Kor Pullover’s pocket layout is also pretty spacious, with a single phone-sized chest pocket on the torso and a kangaroo-style passthrough pocket lower down. This setup is quite cozy for stashing your hands in when things get cold. If you’re looking for a layer with a bit of style (and one that doesn’t skimp on the good materials), the Kor Pullover gets a solid vote.

Another quick-paced option, the Outdoor Research Deviator Hoodie ($255), landed just behind FUTUREFLEECE and Atom SL in our testing and was made to run in. Using a very similar Octa fleece, the Deviator bucks tradition and leans into a body-mapped style to add wind-blocking panels where you need them.

These stretch-woven softshell panels cover the Deviator’s front, shoulders, sleeves, and hood and protect the areas where you’re likely to feel a headwind. Unlike the FUTUREFLEECE, which you’ll need to pop a softshell over to really trap warmth, this hoodie holds heat where you want it and sheds it where you don’t.

While testing on trail runs around Denver last winter, we found the breathability on this jacket to be unreal: “Perhaps the greatest testament to this jacket’s thermal performance was that it kept me dry while running up a half-mile incline that averages 15% gradient,” M.T. Elliott says. “I got sweaty, sure, but I didn’t feel wet when I jogged farther out onto the windy plateau and managed to dry off without feeling cold.”

Tailwinds, it turns out, are the arch nemesis of the Deviator, and can surprise you when running in this hoodie and changing direction. While we’d typically toss a windbreaker on to negate this, we also found that doubling up the fabric over those softshell panels can lead to some sweat accumulation. All this is to say that the Deviator is much better as a solo act, and it’s for this reason we tend to recommend the FUTUREFLEECE more often.

In its lane, however, it’s tough to argue with the Deviator, and for chilly winter runs, it’s an excellent option.