Merrell Thermo Snow Grip Mid Waterproof Hiking Boots Review

I’m picky with winter hiking boots because they can go one of two ways: either they’re light and “fine” until your feet get cold and wet, or they’re warm and protective but feel like you’re clomping around in work boots.

The Merrell Thermo Snow Grip Mid waterproof hiking boots land in a pretty satisfying middle ground for me with comfort I have learned to expect from Merrell.

My pair in a US men’s 9 weighs 18oz / 510g per boot, which immediately tells you what you’re dealing with. This is a real winter boot with structure and protection, but it doesn’t feel bulky once it’s on.

And honestly, they look good too, which matters if you’re wearing them for everyday winter walks as much as actual hikes.

Key specifications

• Price: $126 at Merrell (was $180)
• Weight (my US M9): 18oz / 510g per boot
• Upper: Bellows tongue (keeps debris out), padded collar, protective synthetic heel/toe cap, metal hooks/eyelets, heel loop (also carabiner-friendly)
  • Waterproofing: Waterproof membrane + waterproof suede leather and mesh upper
  • Insulation: 200g PrimaLoft Gold Eco Series synthetic insulation
• Midsole: Super Rebound Compound (shock absorption + smoother transition)
• Outsole: Vibram® Arctic Grip All Terrain + Vibram® XS Trek Evo with aggressive 5mm lugs
• Insole: Removable EVA foam footbed (50% recycled)
• Best for: Winter hikes, cold-weather walks, messy conditions

Note: Merrell’s own disclaimer is basically “use common sense”. These boots can improve traction, but they won’t prevent slipping on every surface, and they don’t replace spikes or crampons when things get properly icy.

Sizing, fit and one break-in spot

They run true to size and bake in a little extra volume for winter hiking socks, and the overall fit has worked very well for me.

The mid-cut shape gives that secure, winter-boot hold around the ankle without feeling overly restrictive.

The only issue was that specific collar edge on the inside ankle.

It isn't a dealbreaker, and it didn’t take long to break in, but it did need a couple outings to soften where it crossed my inner ankle bone.

Once broken in, the comfort improved noticeably and stayed there. No lingering hot spots, no “I hope this doesn’t rub again” feeling, and no need for any hacks beyond just wearing them.

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Performance review

Warmth that feels balanced, not bulky

Warmth is where a lot of winter boots either overdo it (puffy, bulky, stiff) or underdo it (fine until you’re standing around).

The 200g PrimaLoft insulation feels nicely balanced. My toes stay comfortable, but the boot doesn’t feel overly padded or inflated.

I like that because it keeps the overall shape and feel of the boot more “hiker-like” rather than “snow boot-like”. If you’re moving through cold weather on walks and hikes, it hits that sweet spot of warmth without feeling like you’re wearing sleeping bags on your feet.

Waterproofing that actually keeps socks dry

The waterproof membrane + waterproof upper materials are doing their job, and that matters in the real world because winter conditions aren’t always deep snow.

A lot of the time it’s slush, puddles, thawed mud, and wet grass that find their way in.

These will keep things dry enough that you're not thinking about your feet, which is exactly what you would expect from waterproof footwear.

Traction that inspires confidence on typical winter surfaces

Traction is the headline feature on paper, and on foot it’s the part I notice most.

The Vibram Arctic Grip All Terrain setup gives that “I can trust my footing” feeling on common winter surfaces, whether that’s cold wet pavement, packed snow, or those in-between conditions where everything looks harmless until it isn’t.

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Important caveat: I’m not claiming these turn glare ice into a safe surface. Nothing does. If you’re dealing with true ice sheets or steep frozen terrain, you still want spikes or crampons.

But for day-to-day winter hiking and walking surfaces where you’re constantly transitioning between snow, wet ground, and pavement, the grip feels legitimately dependable.

Stable and supportive underfoot, which is what I want in winter

A winter boot doesn’t need to feel nimble like a trail running shoe. It needs to feel stable when surfaces are uneven or unpredictable, at slower speeds. These do that well.

The underfoot feel is supportive and steady, and that gives me confidence that if I’m ever stepping onto awkward snow piles, uneven frozen ground, or messy trails, that I've got the best possible boots to keep me upright.

The boot has enough structure that I’m not feeling every wobble through my ankles, and the midsole doesn’t feel squishy or unstable.

Less flexible than low-cut hikers, but that’s part of the point

Compared to lighter, low-cut hikers, these are definitely less flexible. You feel the extra protection and the winter-ready build. For me, that’s not a negative, it’s just a “know what you’re buying” reality check.

That reduced flexibility is part of why they feel more protective and steady in the first place.

So if you want that nimble, bendy, trail-runner feel, this isn’t it, instead look towards a pair of waterproof all mountain trail running shoes. If you want a winter boot that feels composed when conditions are sloppy and inconsistent, it makes sense.

Looks and everyday wear

I’ll say it: they look good for a winter boot too. Not in a flashy way, just in a “I’d wear these to grab coffee after a cold walk” way.

That matters because boots like this often end up being used for more than hikes, and these have that winter-ready confidence without screaming heavy-duty work boot. That's bumps up their value for money, in my opinion.

My verdict

If you want a ridiculously affordably winter hiking boot (only $126 at Merrell right now), that feels like a proper cold-weather tool, but doesn’t punish you with clunky weight and/or awkward movement, the Thermo Snow Grip Mid has been a really easy one for me to enjoy.

The wins are clear: warmth without bulky padding, waterproofing that keeps feet dry, traction that inspires confidence, and a stable, supportive ride for when winter surfaces get unpredictable. And at 18oz, the weight feels reasonable for what you’re getting.

The only real “worth knowing” is that small collar break-in spot on the inside ankle. Mine softened up quickly and hasn’t returned. Beyond that, the main adjustment is simply accepting what it is: a winter boot, not a nimble low-cut hiker.

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