Gear Review: The North Face Jammu Jacket
The North Face Jammu Jacket
$399, 1 lb. 9 oz. (men’s medium)
Sizes: men’s S-XXL, women’s XS-L (women’s only available online; see bottom of review)
Temperatures well below freezing magnify the challenge of staying comfortable when you’re exerting hard for many hours in the backcountry, in activities like backcountry skiing and climbing. You sweat hard going uphill and get wet; then you lower your exertion level on gentler terrain, or to ski downhill or belay, and you get cold because you’re still wet. What’s needed is a winter jacket that delivers good warmth and protection from wind and flying snow, yet breathes so well that your base layer dries out before you get cold. Enter the Jammu Jacket.
I used it on several winter days backcountry skiing, including on a four-day, January yurt trip in temps ranging from the low teens to the 30s, with a mix of cold wind, sunshine, and falling snow. On the last day of that trip, I wore it over a fleece layer, fully zipped up in temps barely cracking double digits, with frigid wind and alternating sun and clouds as I carried a pack and pulled a sled. In other words, I was constantly transitioning between hot and cold. The Jammu excels in those conditions: It kept me warm when needed, but also kept me from getting too damp with sweat. Most of the credit goes to the extremely breathable Polartec NeoShell fabric, which is fully waterproof (and seams are all taped) but has the supple feel and breathability of a soft shell. To explain it simply, Polartec made NeoShell waterproof enough to keep rain out—it withstands 10,000 mm of water pressure, according to Polartec, whereas some waterproof-breathable membranes are designed for at least twice as much pressure—but not so much that it inhibits breathability. The Jammu’s fleecy lining makes it a bit warmer than lighter jackets, too.
Features are basic but well thought out. There are two zippered, ventilating hand pockets deep enough to carry climbing skins and positioned high enough to avoid a hipbelt or climbing harness, plus a third chest pocket sized for a map or phone. The hood has a fairly stiff brim that fully protects your face, and when zipped up, the collar covers your chin with a soft backing. The jacket lacks pit zips, but I didn’t miss them, given the breathability and the placement of the chest pocket vents. Caveats: It’s too heavy and warm for typical three-season use. And at this price, I’d recommend it mainly to people who go hard in the backcountry in harsh winter conditions; more casual recreationists who don’t need this level of breathability can find more affordable shells. The women’s jacket is sold only in the European Union, but can purchased online through local dealers; see eu.thenorthface.com/tnf-eu-en/women-s-jammu-jacket-4.html.
NOTE: I’ve been testing gear for Backpacker Magazine for 20 years. At The Big Outside, I review only what I consider the best outdoor gear and apparel. See all of my reviews by clicking on the Gear Reviews category at left or in the main menu.