Full cushion and a heavy knit
Full cushion puts padding all around the foot, and heavyweight and mountaineering socks are the thickest knits: Darn Tough’s Mountaineering socks have terry loops through the whole sock, and Smartwool’s Mountaineer Classic Edition carries its maximum cushion label. The heavyweight and full cushion pages list them all.
Leave room in the boot
Try the thick sock with the boots and insoles you will wear. If your toes touch the front or the boot feels tight across the top, choose a lighter sock or a roomier boot.
A cuff above the boot
For cold weather and tall boots, a crew, boot-height or over-the-calf cuff keeps the boot from rubbing your leg and covers the gap under your trousers. A micro crew can be too short for a tall winter boot.
Keep a pair dry for camp
Feet get damp from sweat on cold days too. Keep one pair sealed in your pack for evenings, and do not count it as a walking pair; the trip planner keeps it separate.
What this can’t tell you
No sock carries a temperature rating, and this guide has not measured warmth. The list is chosen by cushion and cuff height; warmth also depends on your boots, how much you move and whether the socks stay dry.
