I backpack in the lower Midwest and Mid-Atlantic states: Ohio, Kentucky, Indiana, West Virginia, and western Virginia. Our climate is best described as temperate three-season, with the occasional winter freeze and, sometimes, a foot or so of snow. I’m rarely higher than 5,000 feet, and usually in the forests. What follows is a general description of the clothing system that works well for me in these conditions. My intention in describing it is to help a beginning backpacker make a reasonable set of purchases for this area of the country. I’m also hoping that folks who have experience in other areas of the country will add to the sub-threads I started (or start others I've overlooked) to help beginners find area-specific advice.

Before we discuss clothing, let’s talk about footwear (even though it’s not technically “clothing.”) I wear trail shoes rather than boots, because my heaviest winter load won’t exceed 25 pounds and my summer load is usually 20 or less, and because I rarely venture off the trail. I don’t need the extra weight and stiffness of full-on boots; you might if you’re carrying heavier loads or scrambling through very rugged terrain off-trail. In the old days when I wore boots, I usually wore a thin pair of polypropylene liner socks, with a thicker pair of wool-nylon blend socks over them. As my foot moved inside the boot, the socks rubbed together instead of my sock and foot rubbing together, thus avoiding blisters – well, mostly avoiding blisters. Now, with trail shoes, I find that my foot doesn’t move enough that I need liner socks, so I just wear a pair of midweight wool-blend hiking socks. I carry one spare set of socks for a long weekend, and two spare sets if I’ll be out for 4 or 5 days. I usually change socks every day, letting the dirty ones air out on my pack. (I’ve never had much luck rinsing my socks out; they usually won’t dry by the time I need them again.) A handy accessory, especially with low-top trail shoes, is a pair of short gaiters: a nylon tube that covers your shoe tops and socks, and keeps debris out of them when you leave the well-groomed trail. Many folks like to carry a spare pair of footwear for fording creeks or comfort in camp, but they’re not really necessary. These can be flip-flops, water shoes, or sandals; again, the lighter the better. My buddy carries a pair of Waldies (similar to Crocs) for creek crossings and camp wear; I may give them a try if I ever feel a real need for camp shoes.

Let’s also talk for a moment about fabrics and fills. As a general rule, garments made of wool or a synthetic (polyester, nylon, and such) are far superior to – and more expensive than – cotton. Cotton holds water, including sweat, while wool and synthetics wick it away. As a result, you don’t chill as easily, which is important for preventing hypothermia in cooler weather. For insulation, you can choose between down or synthetic fills. The pros and cons are identical to those regarding sleeping bags: for a comparable garment, down will be lighter, more compressible, longer-lived, and more expensive than a synthetic garment. Allegedly, synthetic insulation will continue to insulate when soaking wet; down won’t. I don’t think either one will keep you really warm when wet, but it will probably be easier to dry the synthetic than down on the trail. But the real question is: how did you manage to get it soaked in the first place? Keeping your clothes – and other gear – dry is a basic skill you need to learn; it’s beyond the scope of this post, though.

The basic concept of backcountry clothing selection is layering: the use of a base layer, an insulating layer, and a shell layer to adapt to changing temperature and moisture conditions. This also allows you to get the maximum advantage out of the minimum amount of clothing – which saves weight and space in your pack.

My basic outfit is composed of a base layer and a shell: the base layer is a synthetic T-shirt and a pair of synthetic boxer-style briefs, and the shell is a pair of nylon shorts. Until recently, I combined my base layer and shell by using shorts with a built-in mesh liner (like swimming trunks.) However, I’m now experimenting with synthetic or light wool-blend boxer shorts with unlined nylon shorts. I’m finding that this combination is a touch warmer in summer, but prevents some of the chafing on my thighs and groin area that I sometimes experienced with the liners.

As the weather cools, my base layer expands. Instead of boxers and T-shirt, I wear midweight wool or synthetic long underwear top and bottom – think, “longjohns.” My top is a long-sleeved crew neck, though you might prefer a zip-up turtleneck if your neck chills easily. As it gets colder, I’ll layer the long underwear over the briefs and T-shirt for a bit of extra warmth. When it’s downright cold, I’ll use expedition-weight wool long underwear instead of the midweight stuff. (You may prefer to use lightweight polyester fleece garments instead.) My expedition-weight long-sleeved top is a zip-up turtleneck style.

I add a light windbreaker and long pants to the shell layer as needed. My own preference is for zip-off legs, which keep my pack a few ounces lighter, but a separate pair of long pants is an equally valid choice.

When it rains, the shell layer must be waterproof; it may be breathable (though non-breathable also works, just not as comfortably.) Ponchos are an option, though I’m not a fan. If you think you might like them, or if cost is a limiting factor as you assemble your gear, give one a try – just be sure it will cover both you and your pack. My own preference in rain gear is a lightweight waterproof-breathable jacket and pants. Because they are breathable, they can replace the windbreaker and nylon pants in cooler weather, for a bit of extra warmth and a lighter pack.

This system of shell and base layer works well while you’re actually walking. However, when you stop in cold weather (for lunch, a break, or to make camp), you’ll need some insulating garments. If it’s not too cold, a midweight or heavyweight fleece layer may be all you need. As it gets colder, you’ll probably want to add synthetic or down vests, jackets, and possibly even pants, depending on the conditions in which you plan to hike. These don’t need to be heavy, “Michelin-man” style jackets unless you’re going into single-digit or sub-zero temperatures; a “down sweater” or similar weight synthetic will be plenty over your base layer; add your shell layer over the insulating layer for extra warmth. Keep the insulating garments as simple as possible; you don’t need a lot of pockets, trims, side-zip legs, or other gimmicks. A simple front-zip jacket and pull-on pants work very well. I prefer an adjustable hood on my down jacket; you may not want or need one.

What about accessories? Again, you don’t need much. In warm weather, you may not need a hat, though they’re useful for sun protection and, in the woods, for keeping “crud” from the trees from accumulating in your hair. A stocking cap for hiking (I’ve found that a lightweight “beanie” is plenty), and a balaclava (think “ski mask”) for cold evenings in camp or bitter cold hikes is about all I need (but remember, I have a hood on my down jacket and shell garments.) A pair of light liner gloves, some pile or insulated mittens, and waterproof shells will keep your hands warm and dry – cold, wet hands suck almost as much as cold, wet feet. Although most people don’t carry them, I like a pair of down-filled booties to wear in camp in the winter (my feet tend to get cold easily.)

How much “spare” clothing should you bring on a trip? Again, this is a matter of preference. On weekend trips, I bring a change of socks. I don’t get filthy enough that I really feel a need to change shorts, briefs, or T-shirt – but fresh socks at night are sheer luxury! For 4 days or more, I’ll bring two pairs of socks and, sometimes in hot, humid summer weather, I’ll even bring a spare T-shirt and briefs. I no longer bring a change of clothes if rain is forecast; my experience makes me confident that I can keep dry. Until you build that confidence, you may want to carry the extra clothing when it looks like rain. Just remember that each extra piece of clothing adds to the weight in your pack.

Do you need pajamas, or “sleeping clothes”? That’s up to you. I don’t; I tend to just sleep in my hiking clothes (unless they’re wet.) I know a lot of people who do the same, and a lot who sleep naked. It seems to be a matter of personal preference. The same goes for sleeping in socks; if you have a well-insulated foot box in your sleeping bag, they probably aren’t necessary, but you may find them comfortable. Personally, I change into clean socks at bedtime; it’s one of those simple things that make your whole day in the backcountry.

In cooler weather, some folks save pack weight by bringing a lighter-weight sleeping bag (rated for warmer temperatures than those predicted) and sleeping in their insulating clothes. This can be viable way to save weight, but it’s not something I’d recommend to a beginner. If you’re going to try this, you need to control several conditions. First you need to be sure the bag is roomy enough to hold you and your clothes without compressing any of the insulation. Second, you need to be absolutely sure of your ability to keep your clothing dry. If your clothes are wet, they’ll actually make you sleep colder (using body heat to drive out the moisture), and you’re likely to end up with both wet clothes and a wet sleeping bag. So, don’t try this until you have more experience. Personally, I tend sleep in my long johns and take a sleeping bag matched to the predicted low temperatures; knowing I can sleep in my down jacket, pants, mittens, and booties gives me a safety margin when the temperatures fall below predictions.

You may be wondering how you’re going to afford technical clothing on top of the other gear you need to buy to get started. If your funds are really tight, I’ve got three suggestions. First, look at the house brands offered by REI and Campmor; they both carry excellent quality house-brand items that are at the lower end of the price scale. Second, check for used items or similar-function items at home, at discount and second-hand stores, and at garage sales; a wool sweater is just as functional as a wool long-john top, and swimming trunks (except Speedos) work just like a pair of shorts with a mesh liner. Third, if you can’t afford cold-weather garments right away, limit your trips to warmer weather (say, late spring through early fall) when you don’t need long johns and down jackets. You can build your experience and still have a lot of fun, then add the other items as you can afford them and expand your adventures to include colder weather.

Nice post Glenn! My list does not differ significantly. One minor difference is that I do not take shorts because I burn easily and long, lightweight, supplex pants like the Mountain Hardware Canyon pants keep the bugs off my legs. The other is that in bug season I bring a lightweight, nylon, longsleeved shirt soaked in permethrin and in early spring, late fall or mountains I substitute a windshirt instead.

While I now live in the Pacific NW, I grew up in Wyoming and still return there almost every summer. In the high Rockies, you can expect frosty nights and/or snow at any time. Last summer it snowed almost a foot in Titcomb Basin in the Wind Rivers (11,000+ feet) on Aug. 8 and Aug. 15. You probably want either a second additional insulating layer or one thicker one. Daily afternoon thundershowers, often accompanied by strong winds and hail, are common. If you must take a 30* or warmer sleeping bag, take lots of warm clothing to supplement it. You definitely want a warm hat or balaclava and/or a warm hood on your insulating jacket. You also want warm gloves with a water/wind resistant outer layer. However, a pair of liner gloves is better for doing tasks in camp such as lighting your stove, etc. I found out the hard way that I was forever having to take off the thicker warmer gloves, so my hands got colder!

A wind shirt is useful not only in windy conditions, but to keep the nasty horse flies and deer flies from munching you during stops on warm days! Permethrin spray on clothing helps with mosquitoes, but the flies regard it as an appetizer. Wearing a base layer top as a hiking shirt is not a good idea in fly season, either.

While the Pacific Northwest (at least the west side, Olympics and Cascades, are best known for rain, what's not so well known is that between July 5 (or the end of that weekend) and late September, you can count on mostly good weather. Not enough to leave the rain gear at home, though! At higher elevations it can get pretty cool at night. I have seen frost and snow at high elevations during the summer, but they are not common. Once you get to Labor Day, though, things start getting colder and you can start expecting cold and possible snow by mid-to-late September. By late September you had better be prepared for below freezing nights and cold mornings, with an additional insulation layer top and bottom or a thicker single layer. A warm hat or balaclava and warm gloves are essential.

Note that even if it doesn't rain, you will encounter tall grass and brush that will wet you to your waist or higher after a heavy dew. After a rain you may have this problem for several days. We also have such interesting foliage as devils club and stinging nettles. Dress accordingly.

While the mountains of eastern Oregon, eastern Washington and Idaho are considered part of the Pacific NW, they have a more continental climate and are therefore more like the Rockies than like the Cascades.

One method is to stay dry. In most cases this is preferred.

But in warm-wet weather, (think coastal hiking) you are always wet. I found that the best method was to save one set of light-weight underware for sleeping and keep your sleeping bag dry. Simply get wet when hiking. To stay warm in windy-wet just use a wind shirt. Wool is great if you plan on being wet. At the end of the day, wring it out and stuff it in a plastic bag. In the morning, put it on and get hiking. It usually somewhat dries out during the day. If it is really raining and about 68 degrees, I simply hike in rain gear sans clothes. THen jump into my tent, cook in the vestibule, and change into my thin wool sleeping layers. When I did the entire Lost Coast in 8 days, I never really dried out, but was plenty warm.

I guess this points out that each environment you will hike in is quite different. There really is no one "right" answer. Temperature control is a necessity; dry is not necessarily needed.

Honestly, spring-fall I take the same stuff in the pacific northwest as I take in the rockies. because I'm a larger guy, and sweat, and tend to exert myself, I simply take the tack that while hiking I may get moist. I dress to stay warm, rather than completely dry.

In a nutshell my usual gear is poly underwear and nylon pants or convertable shorts, with a poly top, with added layers of a merino shirt and a 100 weight fleece with a windshirt or shell.

when the weather is foul and I'm moving I am most often wearing that, and I let that piece get moist, as long as I am warm.

I have a full set of poly underwear socks, and a merino I keep dry to climb into my sleeping bag with, or change into in camp. Basically my take on it is when I am hiking I may get wet, but stay warm. in my bed I am dry and warm.

Took the same basic gear to tasmania as well, so the tactic also works fine upside down