This year, I ventured to Finnish Lapland, a winter wonderland above the Arctic Circle, where temperatures plummet and the Northern Lights dance across the sky. The key to surviving – and enjoying – the extreme cold wasn’t just thick coats, but the right base layers. These are the unsung heroes of winter comfort, managing moisture, trapping warmth, and making even sub-zero adventures bearable. After rigorous testing in real-world conditions – from dogsledding to frozen lake hikes – I’ve rounded up the best base layers for any cold-weather activity.
Why Base Layers Matter
Base layers are the foundation of any winter layering system. They sit directly against your skin, managing sweat and trapping heat. The right material can mean the difference between shivering through your day and enjoying the winter magic. The key is understanding the trade-offs: merino wool excels at warmth and odor control, while synthetics prioritize moisture-wicking performance.
Our Picks: The Best Base Layers for Every Need
Best Overall: Under Armour ColdGear Mock Neck
If there’s one base layer that proved its worth in Lapland, it was this one. Under Armour’s ColdGear line has a long history of performance gear for athletes, making it a natural choice for Arctic conditions. The smooth, synthetic polyester blend with elastane provides a comfortable, stretchy fit that layers seamlessly under sweaters. The mock neck adds extra warmth without feeling restrictive. While the logo might peek through some outfits, the reliable warmth makes it a top pick.
Best Budget: Thermajane Women’s Thermal Set
This set from Thermajane delivers a top and bottom for less than many brands charge for a single piece – and still performs remarkably well. The soft, polyester-blend material wicks moisture effectively, making it perfect for milder days or as a backup option. The crewneck top and matching bottoms provide a cozy, cloud-like warmth that’s ideal for lounging or light activity.
Best Bottoms: CRZ Yoga Fleece Lined Leggings
These leggings are my go-to for cold-weather layering. The smooth polyamide fabric wicks moisture quickly, while the fleece lining provides exceptional warmth. They layer well under snow pants or jeans, making them versatile for both outdoor adventures and casual wear. Just note that they run a bit long, so adjust accordingly.
Best for Extreme Cold: Smartwool Intraknit Merino 200 Crew
For the coldest conditions, nothing beats 100% merino wool. This Smartwool base layer regulates body temperature effectively, keeping you warm without overheating. The midweight fabric is soft against the skin and wicks moisture well, making it ideal for standing still in sub-zero temperatures.
Best for Hiking: Kari Traa Rose Base Layer
This base layer from Kari Traa, an Olympic champion skier, excels at managing moisture during high-intensity activity. The merino wool and modal blend wicks sweat effectively, while the half-zip design allows for ventilation. The flattering cut and stylish colorways add a touch of fashion to your winter layering system.
Best Socks: Buttons & Pleats Merino Wool Hiking Socks
Don’t underestimate the importance of warm feet. These merino wool socks from Buttons & Pleats provide exceptional comfort and insulation. The blend of merino wool, nylon, and elastane wicks moisture, regulates temperature, and provides a snug fit. They’re perfect for long hikes and cold-weather adventures.
Material Breakdown: Wool vs. Synthetic
Merino Wool: Offers superior warmth, odor control, and breathability. Ideal for low-intensity activities or extremely cold conditions.
Synthetics (Polyester, Nylon): Prioritize moisture-wicking performance, making them better for high-intensity activities or sweaty conditions.
Blends: Combine the best of both worlds, offering warmth, breathability, and durability.
Expert Insight
Gabi Fulcher, a full-time traveler and outdoor adventure creator, emphasizes the importance of choosing the right material for your activity level. “For extreme cold, merino wool is best,” she says. “But for high-intensity activities, synthetics or a blend will keep you drier and more comfortable.”
Final Thoughts
The right base layers can transform your winter experience. Whether you’re braving sub-zero temperatures or enjoying a casual hike, these picks will keep you warm, dry, and comfortable. Choose the material and style that best suits your needs, and prepare to embrace the cold with confidence
