Maya Calderon
There is already much written on the topic of cold weather layering for backpacking and most of it is spot on within the parameters of the article. In my two seasons of cold weather backpacking in Patagonia as well as the Sierras and the Cascades, I have learned to adapt the basic parameters of a cold weather layering system to optimize performance within the parameters of the article. The following article explains each layer, outlines what you should be willing to spend for each, and outlines the biggest mistakes people make when it comes to optimizing a layering system for cold weather backpacking.
Base layer: merino, weight matters
Merino wool at 150 to 200 grams per square meter (g/m2) weight is, to me, the ideal weight for a base layer. There are lighter weights, such as 120 g/m2, but they don’t trap as much air and thus can get too cold. Also, there are heavier weights such as 250 g/m2 and up, but these will overheat you when you are active. The brands that I like to wear for base layers are Smartwool, Icebreaker, and Ridge Merino. All of these brands make great base layers at the above weights. I would suggest that you spend a little money on a good base layer because cheap base layers are scratchy and will irritate your skin. You will hate wearing them.
Mid layer: insulation that breathes
A lightweight mid-layer, or insulating layer, such as fleece (a good option is a 200-300 weight), provides the most versatility when wearing layers actively. It also serves well when not wearing all of your layers as a base layer for camp. Examples of excellent, active insulation are the R1 and R2 pullovers by Patagonia and the high-end option, the REI Fleece Pullover. For stationary situations synthetic insulation performs better and offers greater compression than similar weights of fleece; good options are the Nano Air Down-Alternating Synthetic Insulated Pullover by Patagonia and the high-end option, the Atom LT by Arc’teryx.
Insulation layer: down vs synthetic
Down layers perform best in dry cold. For wet cold (or unpredictable weather) synthetic insulation such as PrimaLoft Gold or Coreloft are recommended because they insulate when wet and weigh less than down layers. 700+ fill power down layers are very light for the amount of warmth they provide. If you can find a good deal on a high-quality down layer such as the Patagonia Down Sweater or the very light Mountain Hardwear Ghost Whisperer then bring it. For shoulder season in Patagonia or for rain in the Pacific Northwest however, a synthetic layer such as the Patagonia Dune Park Insulating Pullover or the Mountain Hardwear Phantom Park Insulating Pullover would be recommended. Book early and bring only one insulation layer.
Shell layer: hard shell vs soft shell
A hard shell (3-layer Gore-Tex or equivalent) is waterproof and windproof, but not very breathable for high-output activities. On the other hand, a soft shell (Patagonia R1 TechFace, Arc’teryx Gamma) is wind-resistant, sheds light precipitation, and is much more breathable than a hard shell for high-output activities. Soft shells are not waterproof in real rain, so for trips with serious weather in the forecast, a hard shell is recommended. For dry shoulder-season backpacking with occasional wind and a few snow flurries, a soft shell is recommended. Both would be overkill for most of the backpacking that I do.
The biggest layering mistake
Do not wear too many layers while hiking uphill as you will sweat through your base and mid layers and get cold when you stop at the summit. You want to dress for the temperature that you will be at 10 minutes into your hike. You will be cold for the first 5 to 10 minutes as you start hiking, that is normal, but if you are warm at the trailhead you will get hot and wet within 30 minutes as you start hiking. Take off layers before you start to perspire.
What I actually carry in cold conditions
I use a Patagonia Capilene Midweight base top and bottom as a base layer, a Patagonia R1 Pullover as my active layer, a Down Sweater as an insulation layer for camp and from time to time during the day, and a 3-layer Gore-Tex hard shell as a shell. This results in 4 layers of clothing above the waist and 2 below. The pack weight for these layers is about 3-4 pounds. These layers allow me to hike in 5F-55F (–15C to 13C) weather. I can always add or subtract a layer or change to a parka or to light weight insulating layers and a different shell for colder or warmer weather. This layering system has proven to work well in Patagonia’s spring weather as well as in the Sierra’s late summer.
