Pro tip: water sources on the JMT in August are farther apart than the maps show
Honestly I did the Rae Lakes loop over 4 days in early August and the water situation was way different than I planned for. The map I printed showed a creek every 2 or 3 miles but by the second afternoon at least 3 of them were totally dry, just sand and rocks. I ended up walking 11 miles from Woods Creek to the next reliable source with only half a liter left, which was dumb and got scary. A ranger at Charlotte Lake told me late season snowmelt runs out faster than the topo maps get updated, so the blue lines lie. Now I carry a full 3 liters between fills and treat every marked creek as maybe water, maybe not. Has anyone done the same stretch in September and can tell me if it gets even worse?
September is way worse, I did Woods Creek to Paradise Valley last year around mid month and two creeks that were running in August were bone dry. Plan your fills around the lakes and bigger crossings since those hold up longer, and just top off every chance you get even if you feel dumb doing it. Carrying 3 liters as your baseline is smart, I do the same thing now and it saved me on the last trip.