Smartwool Classic Thermal Merino Base Layer Review
The base layers I keep coming back to for skiing, from snowy storm days to bluebird days.
Words by Michele Underwood | Photos by Michele and Smartwool
A day on the slopes at Beaver Creek.
I have tried a lot of different base layers for skiing over the years, and nothing has beaten my Smartwool Classic Thermal Merino layers. I wear the Classic Thermal Merino Crew Base Layer Top with the matching Classic Thermal Merino Base Layer Bottom, and they're the pair I know I can count on. I've worn them on super snowy ski days when staying warm matters, but I also wear them on those beautiful bluebird days when the sun is out, and I'm moving more. They just work.
I guess there is a reason they call it Smartwool. Ha.
What I like most is that I don't have to think that much about them. I put them on under my ski clothes, and I'm comfortable. Merino wool helps regulate temperature rather than just trapping heat, which makes a difference when I'm going from sitting on a cold lift to skiing and generating heat again.
I remember one day at Breckenridge — cold and stormy, the kind of day where riding the lift can be brutally cold once the wind picks up. My shell kept the wind and snow at bay, but it was the base layers underneath doing the real work keeping me warm. That's the day I stopped thinking of these as just something I put on and started actually trusting them.
After trying other brands, these are the base layers I keep going back to. My setup is the Classic Thermal Merino Crew top and matching bottom, both made with 100% merino wool in Smartwool's heavier 250 g/m² fabric — Smartwool's warmest weight, built for exactly the cold-weather days I bought them for.
The Smartwool Base Layers I Wear
The Smartwool Classic Thermal Merino Crew top I wear.
The matching Classic Thermal Merino bottoms.
My ski setup is the Smartwool Classic Thermal Merino Crew Base Layer Top – Women's and the matching Smartwool Classic Thermal Merino Base Layer Bottom – Women's.
Both are made with 100% merino wool in Smartwool's heavier 250 g/m² fabric. They're designed for cold-weather use, which is exactly why I bought them for skiing.
Smartwool Classic Thermal Merino Base Layer Facts
100% merino wool
250 g/m² fabric weight
Slim fit designed for layering
Flatlock seams to help reduce chafing
Crew-neck top
Matching full-length bottoms
Designed for cold-weather activities
Women's fit
Why I Prefer Merino Wool for Skiing
Bundled up in my Smartwool Classic Thermal base layers under my shell on a cold, stormy day at Park City — exactly the kind of day these are built for.
The biggest thing for me is temperature regulation. Skiing isn't a constant level of activity. I can be cold riding a chairlift and then warm up quickly once I start skiing.
That's where these seem to get it right.
The Classic Thermal Merino is warm enough for the cold and snowy days I bought it for, but I don't feel like I have to save it only for those days. I've worn the same layers when the sky is blue and the weather is much nicer.
That versatility is a big part of why I like them so much.
How They Fit Under My Ski Clothes
A base layer needs to disappear once I put the rest of my ski clothes on. I don't want bulky fabric underneath everything or layers that bunch up and become annoying halfway through the day.
The Smartwool Classic Thermal layers fit close to my body, which makes them easy to wear underneath my ski jacket and pants. Once I'm dressed, I'm not thinking about my base layers anymore.
For me, that's exactly what a good base layer should do.
Are Smartwool Base Layers Worth It?
For me, yes.
I've tried enough other brands that I don't say that simply because these are the base layers I happen to own. I've had other options, and Smartwool is what I prefer to wear skiing.
They're warm, comfortable, easy to layer and useful across a wider range of ski conditions than I initially expected. Instead of having one setup for bitter cold and another for nicer ski days, I can reach for these most of the time.
Sometimes the best gear is the gear you stop thinking about once you're wearing it. That's where these land for me.
If You Want to Grab a Pair for Yourself:
I write Overland Girl, where I share firsthand travel experiences across the American West — from desert landscapes and national parks to small towns layered with history. My work blends movement, place, and the stories that shape them.
Some posts may include affiliate links to products or services I use on the road. If you choose to purchase through those links, I may earn a small commission at no additional cost to you. It helps support continued travel and storytelling. I only link to items I personally use or would use myself.