I think a backpacker’s impression of the White Mountains in New Hampshire is largely dependent on the weather. Basically, the Whites can be described as a series of three ridges: the Franconia at the south, the Presidential (which includes Mt. Washington) in the middle, and Wildcat at the north end. The Franconia and the Presidential offer extended travel above tree line. Wildcat is not as high as the others, but sport some very steep pitches. Storms with high winds, cold temperatures, rain, snow, and lightning can occur at any time. I can tell you first hand that the backpacker who traverses one of these ridges during such a storm will not have a pleasant experience. The trails above tree line are marked with cairns (piles of rocks) spaced so you can usually see the next cairn from the one before it. The trail above tree line on the Presidential Ridge is very rocky. That is why they were able to build so many cairns! During rain, extra concentration is required to navigate the slick rocks safely.
You could travel above tree line during moderately bad weather if you have good cold weather gear (i.e. rain suit, sweater, gloves, wool socks, and long underwear), but not during thunderstorms or high winds. I hiked through a three-day storm while on the Presidential Ridge during August. The bad weather came from the south, so the wind was mostly at my back. A lot of the trail was built on the leeward sides of the ridge lines to afford protection; even so, I wouldn’t want to hike when gusts exceed 40 mph.
I highly recommend that you lodge in the huts during inclement weather. They are spaced a reasonable day’s travel apart. Don’t be surprised if your daily mileage shrinks to 7 or 8 miles during bad weather. The huts are operated by the Appalachian Mountain Club under contract with the U.S. Forest Service. They are large and rustic. They consist of a dinning hall, kitchen, non-flush toilets, and several bunk rooms. Lake of the Clouds Hut near the summit of Mt. Washington bunked 94 paying visitors the night I stayed there. Electricity is supplied by generators. Heat is produced by fireplaces. All food and garbage is packed in and out by the staff (i.e. cru). If you ask one of the cru for a napkin, he will stare at you like you requested the head of the wicked witch of the west.
If you arrive at a hut too early in the day, the hut master will probably deny you lodging. They want to keep thru-hikers moving through the hut system so they don’t pile up. Thru hikers were always welcome, however to rest at the huts, replenish their water supply, and purchase soup for two dollars a bowl. I don’t think any hut master would deny lodging to a thru-hiker arriving after 4 pm, especially on a stormy day. My hut stays followed a common routine: arrive after 4 pm, request work for stay, sit on a bench in the dining hall and watch all the paying guests eat, pig out on the leftovers, work for about an hour (e.g. clear tables, give a talk about your hike, or clean some appliance in the kitchen), sleep on the dining hall floor, watch the paying guests eat breakfast, pig out on leftovers, work for another hour (e.g. clear tables, or sweep bunk rooms), and leave at about 10 am. Work for stay was granted to all thru-hikers when I was there. There were eight of us at Lake of the Clouds Hut, and four at Madison Spring Hut.
Most of the paying guests were families and retired folks from the Boston area. At first, they seemed to avoid us; however, after a thru-hiker gave an evening presentation, they became very friendly. Several offered us their extra food, and showed a great interest in our hikes. I got to know some of the guests pretty well because they traveled the same direction along the AT as me so we spent consecutive nights at the same huts.
During nice weather, I usually stayed at established campsites. They consisted of a caretaker’s tent, a privy, several tent platforms, and a water source. Platform space was limited, so it was common to share one with several other tents, wall to wall. No camping was allowed on the ground. The tenting areas charged $8 per night. I had no problem pitching my tent on the platforms even though it was not free-standing. There was enough space between the boards to wedge my stakes between them. The platforms always had eye-bolts along the edges to which one could tie off the tent corners. Some of the campsites provided bear-proof food lockers, while others had no bear facilities. Bear problems were uncommon in the Whites.
I decided to stealth camp (i.e. tent illegally) one evening when darkness caught me before a steep descent to the next campsite. I chose a site below tree-line and out of view of the trail. If you need to stealth camp, you can minimize your impact on the fragile, overused ecosystem by waiting to use a privy at the next hut or campsite.
The AT follows older trails through the Whites. They were constructed in the early 1900’s, when switchbacks and erosion control were apparently not in the repertoire. The result is very steep, treacherous trails that have eroded down to bedrock or boulders. Plan to pack as light as possible. The hut system and visitor centers should allow you to carry less food than usual. I was able to resupply at the visitor centers on Mt. Washington and at Pinkham Notch. The selections there were very limited (candy bars and trail mix), but I got plenty of good food from the huts.
The White Mountains are a unique part of the AT experience. If you take it slow, enjoy meeting new people, utilize the huts during poor weather, and come prepared with cold weather gear, you will probably prevent your name from being added to sizeable list of tourist fatalities displayed in the visitor centers.