Men’s adidas Terrex Skychaser AX5 Mid GORE-TEX CLIMAWARM+ Boot Review

Bottom Line

The Terrex Skychaser AX5 Mid GORE-TEX CLIMAWARM+ is the winter version of a new entry-level hiking boot that adidas Terrex released earlier this year, the Skychaser AX5. It fills a cool niche: a lightweight boot built with colder weather in mind. Rather than emphasizing breathability, the Skychaser focuses on warmth and protection, making it a great option for anyone who runs cold or hikes in chilly conditions. After testing, we think it lives up to the hype.

The synthetic upper is tough – far more rigid and structured out of the box than we expected. It’ll need some break-in time before you take it on more rugged or high-mileage trips. That said, the DWR-treated upper, paired with a GORE-TEX membrane and CLIMAWARM+ insulation, did a great job keeping out the elements. Our feet felt toasty on frosty mornings and snowy trails.

The main downside is the fit. Like most Terrex models, the insulated Skychaser AX5 runs small. We found it runs about a half size short. Unfortunately, there are no wide sizes available. If you require a wide fit, this boot may not be for you.

How We Tested

We tested the adidas Terrex Skychaser AX5 Mid GORE-TEX  CLIMAWARM+ boots primarily during early to mid-fall across Colorado’s foothills and alpine trails. Lucky for us, it was an unusually wet and chilly season, which gave us a great opportunity to evaluate these winter boots in cold, damp, and even snowy conditions. We put the insulation, traction, and waterproofing to the test in real-world scenarios – from muddy lowland paths to frost-covered, high-country trails.

Comfort

The Skychaser AX5 CLIMAWARM+ feels warm, secure, and surprisingly plush once broken in. Out of the box, we found the upper, especially the ripstop portion, to be pretty stiff. It softened up nicely over time, but it took about 20 miles before the boot really felt dialed in. 

The interior is lined with Adidas’ CLIMAWARM+ insulation, which adds noticeable warmth without making the boot feel bulky or overbuilt. We tested these boots on chilly fall mornings and snowy alpine trails in Colorado. They impressed us by keeping out the cold and moisture. That said, the boots can overheat in milder conditions – they’re made for winter, not spring, summer, or fall.

While initially rigid, the supportive structure paid off during long trail days. The midsole is well-cushioned and decently responsive, offering solid comfort on high-mileage hikes without feeling overly soft. The boot hugs the foot securely, and the GORE-TEX liner kept our feet dry through snow, rain, and muddy trails. We recommend giving them a few miles to break in before committing to a multi-day backpacking trip, especially if you’re prone to hot spots.

Fit will be a limiting factor for some. Like most adidas Terrex models, the Skychaser AX5 CLIMAWARM+ runs small with a relatively narrow fit. We recommend sizing up at least half a size, particularly if you’re between sizes or wear heavier socks in colder weather.

Ankle Support

The Skychaser AX5 CLIMAWARM+ offers solid but not exceptional ankle support for a lightweight hiking boot. Like most models in this category, it doesn’t have the structure or rigidity of a traditional leather backpacking boot, but it still provides a decent level of support where it counts. We’d call it moderate: enough to inspire confidence on mixed terrain, but not so stiff that it limits agility.

We wore these boots on uneven alpine trails in Colorado, often with a pack, and found them supportive enough to help stabilize the ankle during sidehill travel, mild scrambling, and technical descents. The cuff is flexible but hugs the ankle tightly and gives it a dialed-in feel.

For fast-moving hikers and backpackers sticking to established trails or venturing into moderate off-trail terrain, the ankle support here should be sufficient. But if you’re prone to rolled ankles or carrying a heavy load across rugged alpine environments, you might want to consider something with a taller and stiff cuff.

Weight

It’s not the lightest boots in our lineup, but the Skychaser AX5 Mid has an impressive weight-to-warmth ratio for cold-weather use. According to adidas, these boots weigh 16.8 ounces per shoe (roughly 2.1 pounds per pair) for a men’s US size 9. Our size 13 test pair weighed in at 2 pounds 10 ounces per pair. 

They’re on the heavier side compared to the other hiking boots on our list.

That said, direct comparisons with true three-season boots like the Salomon X Ultra 5 Mid GTX or the Oboz Katabatic LT Mid GTX aren’t entirely apples-to-apples. The Skychaser is built with added insulation for winter-like conditions – which contributes to the weight. Despite these cold-weather features, the insulated Skychaser AX5 still manages to feel light and agile underfoot – which is a standout feature.

For hikers looking for a winter-ready boot that doesn’t feel clunky, the Skychaser AX5 CLIMAWARM+ is a good choice. It’s heavier than some mid-height hikers but significantly lighter than full-on winter boots.

Traction

The Skychaser AX5 CLIMAWARM+ offers dependable traction overall, but it does have a few quirks. We found it to be confidence-inspiring on dry trails, rocky alpine terrain, and hard-packed snow. On classic Colorado hikes with a mix of loose dirt, gravel, and granite, the boot held its ground really well – no slipping or second-guessing – even when moving quickly.

Things got a bit more hit-or-miss in wet conditions. On damp trails and muddy switchbacks, the outsole gripped reliably, and we had no trouble maintaining footing through wet grass and duff. It even held up well on slick granite during a couple of rainy hikes. But as soon as we hit wet lichen or moss-covered rocks, traction dropped off. The same goes for wet wood—footbridges, roots, and boardwalks were noticeably slick.

That said, these boots are excellent on snow. We tested them in early-season conditions and were impressed by how well they handled both untracked and packed trails.

Weather Resistance

The Skychaser AX5 CLIMAWARM+ Mid is built to keep the elements out, and it does an impressive job. Between the GORE-TEX waterproof liner and the CLIMAWARM+ insulation, this boot is clearly designed with cold and wet conditions in mind. 

We tested it during an unseasonably wet and chilly fall in Colorado and made a point to hike directly into the rain and snow to see how it performed. We were genuinely impressed with how well the waterproofing held up over time. Light snow and wet trail conditions posed no challenge. Even after several hours of hiking in consistent rain, our feet stayed dry. In fact, these boots outperformed our expectations in both light snow and puddle-ridden terrain.

That said, we did notice one weak point: after prolonged exposure to rain, the fabric just below the ankle started to show signs of soaking through. Moisture didn’t immediately breach the waterproof liner, but the outer material began to feel saturated.

Still, for winter trail use, the Skychaser AX5 CLIMAWARM+ offers excellent protection. It’s one of the better-performing waterproof lightweight boots we’ve tested for cold, wet conditions. Just be aware that in extended heavy rain, especially if you’re on the move for multiple days, some saturation around the ankle collar could eventually catch up with you.

Durability

Although the Skychaser AX5 Mid GORE-TEX CLIMAWARM+ is still relatively new, our early testing shows promising signs for long-term durability. With a few hundred miles already on our test pair, we haven’t encountered any major issues—no delamination, no blown seams, and no significant wear in high-stress areas.

The ripstop synthetic upper feels tough and abrasion-resistant, and we like that there isn’t a lot of exposed stitching to worry about fraying. Reinforced overlays around the toe and heel also help protect against scuffs and trail abuse. 

That said, it’s still too early to make a definitive call on long-term performance. We’ll continue testing through the winter and beyond, especially to see how the upper material fares at flex points and beyond. But so far, the build quality seems solid.

Should you buy the adidas Terrex Skychaser AX5 Mid GORE-TEX CLIMAWARM+ boot?

If you’re after a cold-weather hiking boot that doesn’t feel like a heavy-duty clunker, the adidas Terrex Skychaser AX5 Mid GTX CLIMAWARM+ is definitely worth checking out. It’s warmer than your average three-season boot but still feels nimble and light on your feet. We really liked the combo of solid insulation, waterproofing, and sure-footed traction. It handled frosty mornings, light snow, and damp trails like a champ.

That said, it’s not a quiver killer. If you’re hauling heavy loads, heading deep into the alpine, or need a roomier fit, you’ll probably want something stiffer or more spacious. And, of course, this is a poor choice for summer and fair-weather hikers.

Overall, though, the winter version of the Skychaser AX5 offers a lot of performance for the weight. You get legit weather protection, good structure, and comfort in a package that’s surprisingly sleek for a winter boot. For cold hikes, snow-dusted trails, or anyone who tends to get chilly feet, this is a great option.

What other hiking boots should You consider?

If you’re looking for non-insulated hiking options, please check out our guide to the best hiking boots for more options.

Salomon X Ultra 5 Mid GTX Review: This is the natural sibling to the Katabatic. You’ll get a similar light, fast-moving feel, but the X Ultra 5 adds a little more structure and support. If you want something that’s still nimble but a bit more locked in for steeper terrain, this is a solid step.

HOKA Anacapa 2 Mid GTX Review: Like the X Ultra 5, these boots are lightweight with a narrow fit and a responsive feel. But if comfort is top priority, the Anacapa 2s are the winner with their forgiving foam soles and superior traction. They offer a flexible, nimble experience that’s perfect for hikers who want speed over harsh weather resistance and durability, making them ideal for moderate conditions.

KEEN Hightrail Mid WP Review: For those who want more ruggedness and a bit more room, the KEEN High Trail Mid WP delivers. It trades some lightness for durability and toe protection, and the WP (waterproof) model adds confidence when trails get wet or sloppy.