I go to Big Bend each summer. We always stay in the basin in one of the stone cottages and have thoroughly enjoyed it. Chances of rainfall increase during July and August, although we have made trips in both those months in the past and have had no weather problems (rained one day, but was great the rest of the time). Temps in the basin, even in summer, are not a problem. We have done the Window, Pinnacles, Laguna Meadows, and Lost Mine trail in the summer with no difficulty whatsoever. Of course, one must always carry water and plenty of it. Now...in the summer, you do have to watch the hiking in the desert. Trails such as Grapevine Hills, Hot Springs, Chimneys, Mule Ears, Burro Mesa Pour-off are best done early in the morning (get on the trail by no later than 8AM) as you do not want to be on one of the desert trails in the afternoon with no shade - that can be deadly and every couple of years or so, a hiker seems to die out there from dehydration. One advantage of going in the summer -- it is not crowded at all.
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