Do most people bring tents on the JMT or just tarps? I figured the main thing I can do to make my pack lighter would be to either get a lighter tent or use something other than a tent for shelter. (I have a Mountain Hardwear Thru Hiker, by the way.) I like my tent I have and I don’t mind its extra weight (approx. 5lbs), but all the ultralight talk makes me think I should try to be as light as possible. 
I’d appreciate any opinions or advice.
naturegirl
I have used both a silnylon tarp and an REI half dome tent on different long Sierra hikes. Normally you will see nothing more than occaisional afternoon/early evening thunder storms in the summer. That being said, we had 12 straight days of moderate to severe thunder storms on our July, 2006 JMT hike and were glad we brought the tent.
Several years earlier we spent a loooong stormy night at 11,000 feet under our tarp praying the winds wouldn’t shred it. It held up, but the next morning I told my son that if I ever suggested using a tarp on a long trip again he was to slap me. He reminded me of that when I was trying to shave weight for our JMT hike. Since he offered to carry the tent, it was an easy decision to make.
I still use the tarp for short trips when the forecast is for good weather. It all depends on what you want to have on your back versus what you want for shelter if a big storm hits.
Snowball
The most popular reason for bringing a tent is to escape the mosquitoes. If you bring a tarp, make sure you have some type of netting or a bug bivy.
If you hike later in the summer they aren’t as thick.
Snowball
For me, the primary consideration is bugs. I don’t like to deal with skeeters when I’m trying to sleep. So for me, a tent. I carried a borrowed Stephenson Warmlite in '06, and will either carry my MSR Missing Link, or purchase my own Warmlite this year.
I suppose there are bug proof tarp systems - using a bivy or mosquito netting. I’d be interested to hear other people’s experiences with systems that worked.
JH
On my JMT hike last Sept. I carried a Tarptent Contrail and it worked fine. I didn’t need it for weather, as i only had 1 hour of rain the entire trip. The bugs were dead by Sept so that didn’t concern me. I suppose it kept me a little warmer and kept the wind off of me, but I’m glad it was light because I probably didn’t need it. If you’re comfortable with a tarp that should work fine for you. I didn’t see many tarps on my trip. At the end of my hike I was in the first storm of the season on Whitney and my Tarptent was useless, so I was lucky to share a tent with some friends.
weez