These are the warmest wool base layers I’ve found. They all feature a high percentage of very fine and warm wool.
Glossary
g/m2 — grams per square inch (the weight of wool in the garment)
micron — the symbol “μ”– one million of a meter — the diameter size of the hair in the wool — also known as “fineness”
Warmest Wool Base Layer Tops (Men’s)
- 100% Yak Wool Crew Base Layer by Kora – 230 g/m2 yak wool — $145
- 100% Merino Heavyweight Crew by Woolx — 18.5 micron — 400 g/m2 — $120
- Icebreaker Tech Top Long Sleeve Crew by Icebreaker — 260 g/m2 superfine merino – $110
- 100% “Royal” Alpaca Base Layer by Arms Of Andes — 18 micron wool — 230 g/m2 — $105
Warmest Wool Base Layer Bottoms (Men’s)
- 100% Yak Wool Leggings by Kora — 230 g/m2 yak wool — $145
- Katmai Men’s Expedition Weight Bottom by Minus33– 400 g/m2 — 18.5 micron merino wool — $120
- 100% Heavyweight Merino Leggings by Woolx — 400 g/m2 — 18.5 micron merino wool — $120
- 100% Superfine Merino Wool Apex Leggings by Icebreaker — 260 g/m2 super merino wool – $110
- 70% Merino Wool Leggings by Hocosa — made in Switzerland — 70% KbT-certified organic merino wool & 30% silk — $100
- 70% Merino Wool Leggings by Ecoable — 70% organic merino wool and 30% mulberry silk (GOTS Certified) — $60
- 100% Merino Wool Leggings by Sheep Run — 18.5 micron wool — 230 g/m — $50
- 95% Merino Wool Leggings by Zhili — 95% merino wool and 5% polyester fiber — $90
Warmest Wool Base Layer Tops (Women’s)
- 100% Yak Wool Crew by Kora — 230 g/m2 yak wool — $145
- 100% Merino Heavywight Crew by Woolx — 18.5 micron merino wool — 400 g/m2 — $104
- 100% “Royal” Alpaca Base Layer by Arms Of Andes — 18 micron alpaca wool — $105
- 100% Superfine Merino Baselayer Top — 260 g/m2 — $82
Warmest Wool Base Layer Bottoms
- 100% Yak Wool Leggings by Kora — 230 g/m2 yak wool — $145
- 100% Heavyweight Merino Leggings by Woolx — 400 g/m2 — 18.5 micron wool — $104
- 100% Merino Wool Leggings by Lapasa — $86
- 100% Merino Wool Leggings by Meriwool — 200 g/m2 — 18.5 micron wool — $60
- 70% Merino Wool Leggings by Engel — 70% merino wool and 30% silk — $65
- 70% Merino Wool Leggings by Ecoable — 70% organic merino Wool / 30% Mulberry Silk (GOTS Certified) — $60
- 40% Merino Wool Leggings by Zhili — 40% merino wool, 45% viscose and 15% polyester fiber — $70