The Altitude (fleece ones) are perfect for temps 0-20°F / (-7 to -17°C) and the Rainier (brushed ones) are great for 20-40°F (-7 to 4°C). Both temperature ranges depending upon if you run hot or cold. I wear an XXS in both as I feel they run a little on the big side, so check the size chart. Both are on sale now: $69 and $59, respectively. ✨