Loc: Santa Cruz CA, Sierra Hiker
So I used to have a base weight (sans food and water) of 12 lbs. I was more or less happy with that for several years. Then I didn't go backpacking for a couple of years cuz my daughter had 2 kids in a row and was due in the summers and I didn't want to be in the high country when she went into labor. Now I am going again shortly, and I just went thru all my gear and did a practice packing and it climbed to 15 lbs! What on earth? I know I swapped out my driducks for precips cuz they were ripped....but I also saved lbs elsewhere. Did someone stuff rocks in the bottom of my pack or what?:)
Maybe your 12 lb base weight was an optimistic illusion! Are you sure you counted everything in the past? Are all those little things in your pocket now counted as base weight?
I found that weighing stuff is variable. I have a good postal scale, yet I get slightly different weights each time I weigh stuff. Of particular note is larger stuff that can ooze off the weighing tray reducing the weight. I also found that if the item is centered on the scale, it does not weigh accurately. I have the opposite - stuff weighed years later weigh less!
Have YOU increased in size? If so those clothes, the next size larger, will also weigh more.
If you are use manufacturer's listed weight, often this is sandbagged to the light side. Tent is a perfect example. The tent has to include everything you use - strings, pegs, ground cloth if you use it. Most "weights" stated for tents are bogus. Sleeping bag - got to be stuffed so the weight really should include the stuff sack. Shoes are another example - often the listed weight is of ONE shoe - now who only wears one shoe!
Theoretically, based on the amount of lint I clean out of the dryer, clothing should weigh less as it is washed over and over. Hey, if you never wash anything, and dirt collects, over time it weighs more!
Loc: Washington State, King County
I think the only way to know for sure is to maintain a gear spreadsheet with specific (and yes accurate) weights.
I tweak such a spreadsheet for every hike, pack according to the list, and then weigh the aggregate on a hanging scale and always find the result within a quarter pound or so of the sum of the listed weights.
That sounds pretty geeky/obsessive, but it really doesn't take all that much time now, and I never ever find on-trail that I've forgotten something, and I've also gotten better and faster about making gear functionality/safety/weight trade-offs in planning a trip.
Electronics certainly can be a factor. Food should not be if talking about base weight. I find variations in all of the categories on a per-trip basis. Anticipated colder, wetter, and/or more buggy conditions all impact the shelter, sleeping system, and clothing choices. Hiking with a group vs. hiking solo or with others who have the same 'style' ditto. Cooking or going stoveless impact baseweight as well as total weight. Base camping vs. going for more daily distance too. Hiking in significant snow could add microspikes and/or a light ice axe (or self-arrest pole, which latter is part of skin-out but not base weight).
I think my base weight varies on a per-trip basis from about 12 to 17 pounds depending on all of these factors. Probably even higher yet if I do any snow-intensive trips with groups.
Humidity would also have an impact on weight. Virtually everything we carry will absorb water and that extra water will add weight. However, I think that I agree with others that the original weigh-in was probably off.
Loc: Gateway to Columbia Gorge
I do what BrianLe does and find it helps prevent "pack creep." There's always that little thing we stuff in--enough of those can really send the weight up! At least with the spreadsheet, I can make an informed (more or less) decision as to whether I want to take the extra stuff.
May your trails be crooked, winding, lonesome, dangerous, leading to the most amazing view--E. Abbey
Loc: Meadow Valley, CA
I was amazed how much my empty pack weighted the morning I came out after a week in the wilderness. Was there that much gargage? I only picked up a few errant bits of someones garbage also. Here I thought my base weight was down under 8 lbs. or so for summer trips in the Sierra. Duane
Are you using the identical gear you used a couple of years ago? If you've replaced some things, or added some things, that will change the weight.
I find, from year to year, that I tend to add things, "because it's only half an ounce (or two ounces, or whatever.)" I'll convince myself that the stove that used to live in my food bag needs its own stuff sack, or that having an extra collapsible water bottle could come in handy someday. A monocular is fun to take, or a set of toenail clippers is handy, or maybe I decide I should increase the number of matches or ibuprofen or safety pins I take - and the next thing I know, my pack is a pound heavier than it used to be. So, I get ruthless and ferret out all the culprits and eliminate them. And then, a couple of years later, repeat the cycle.
And then there's the obvious: are you using the same set of scales you used two years ago? (Ask any handyman why you don't measure with your tape, and use your buddy's tape to mark the board.)
Loc: Santa Cruz CA, Sierra Hiker
I guess it could have been optical illusion. I did have a complete list with the weights listed on each item. Unfortunately, I switched computers and lost the list. But...I did have a list without the weights still and I think the stuff I have is identical except a couple things. I took out the driducks as the pants had split. I replaced those with heavier pants and jkt (15 oz total ). But then I cut the weight of my books I usually bring in half with a kindle. I added a steripen when I usually don't bring anything but a few tabs of iodine and vit c...I can't think of anything else that would have made up the 3 lbs. I am going to go thru my stuff again in a day or so and see what I can do to repair the damage!:)