Staying warm/dry in Sept on the JMT

I wouldn't worry too much about the overall weather pattern that is shaping up. Effects of the el nino will not really be felt until winter. With that said, this has been an anomalous summer where the typical week (maybe) of good rains in the Sierras have stuck around a little longer. By the end of August/Sept. you will likely see a typical pattern which is dry warm days and chilly nights.

I just got back from a two week thru of the JMT with a week of the cruddy weather.

Frogg toggs will likely be fine. I walked in all day rain in a golite poncho and it was fine 90% of the time. Only when it got really windy did I hate the poncho.

The zpacks liner is a good idea, the pack cover probably wont be necessary. I wouldn't bring both.

The thermoball jacket will likely be enough but I don't have the jacket so I'm not sure how warm it actually is. I got by with a MEC t2 and stoic hooded hadron down jacket in camp. Only wore the down jacket a few nights.

I was plenty warm with my 30 degree zpacks quilt. Not cold a single night. But I do generally sleep warm.

I wouldn't worry about having wet feet on the JMT. It really should be your last worry. I wore salmon trail runners and had 2 extra pairs of socks in my pack, at least one dry at all times. Worked fine for me even with wet feet for 5 days.

Thanks Arn – bummer you got stuck in all of that craziness! Did you get stuck in that snow at Whitney?

By mid-Sept nights on the JMT can definitely drop down to 15 degrees, so I'm probably gonna play it safe with the 15 degree bag. I wish I was a warm sleeper!

I'll definitely take advice on the Frogg Toggs (and maybe look at the Golite poncho as an alternative). is the poncho big enough to fit over your pack as well?

My thoughts with the wet feet (because, obviously in the sierras that is never anywhere near the top of the list of issues!) is what my plan of action will be if stuck in a multiple day weather event like you guys ran into. I'm guessing there isn't much of a choice other than to hike with wet feet, but leave a pair of dry socks in my bag for nights?

first of all, if you have a pack liner, why do you need to then also cover your pack? The important stuff stays in the liner, nice and snug and dry, and everything else goes, well, everywhere else and gets wet.

I'm also keen on taking the warmer sleeping bag – I had Tim add some extra down to my 20 deg enigma because I'm such a cold sleeper. I'm also bringing my down booties because, well, they're simply fabulous.

Hiking for days at a time in wet feet really isn't that bad – as long as you have something warm and dry to change into at the end of the day. You walk, your feet are generally wet with sweat and grime and dust and all sorts of nasties anyway….get to camp, change into nice dry, warm clothes, cuddle up in your warm, dry bag in your warm, dry tent and enjoy!

I don't have experience walking in the Sierra all wet, but I've done a ton of backpacking in some nasty, nasty weather all over the world and basically you just walk wet, sleep dry.

As long as you're moving during the day and have warm/dry stuff to wear when you stop moving you'll be just fine.

yeah, being wet isnt bad as long as you can get dry. Ive never noticed any difference whether my feet were wet or dry.

Keep a dry pair of socks and long johns in your pack, and put them on when you stop. In rainy climates, always have dry clothes to put on at end of the day. Not normally an issue for the sierra, but this yr seems to be so.

I was quite chilled after hiking in cold rain half a day on the JMT. My previous 3 days had been 20-25 mile days and I was gettiing a bit tired out, so I stopped after about 10 miles one rainy day, put on dry stuff, got under my quilt. Still took me about 1.5 hrs to warm up good to where my feet were toasty, and that was middle of the day.