Two things work against us here: altitude and slope. Down amongst the ponderosa pines it can get awfully hot. And for the most part, this warm section of the John Muir Trail is an uphill adventure. To be fair, it's not the steepest of hills. The only intense segment is the cluster of switchbacks climbing up out of Goddard Canyon to Evolution Valley. But unless you hit the first part at a forgiving time of day, or during early or late season, it can get pretty warm. From the Florence Lake area, the trail winds in a most unhurried manner to the Piute Creek Crossing. After the crossing, the gradient remains moderate, but again, the deep, rocky canyon can get incredibly warm. Since Evolution is a "hanging valley" there's no simple way in. The trail gets steep and switchback-y here for a good mile or two, but as usual, the higher you get (in altitude) the better the views. The toil is incredibly worth it. Soon after leveling off you get to the Evolution Creek Crossing, which, as far as we've been able to tell, is a wet ford no matter what you do. And then you're in the famed Evolution Valley with its expansive, glorious meadows. The trek through the valley has its uphill spurts, but for the most part, the journey is mellow. However, if you've brought DEET along, or citronella or your own personal full-body mosquito net, now's the time to use it. Late season the mosquitos aren't so bad, but the population is denser here than most other segments of the trail.
If you're headed North, you've just dropped out of the Evolution Basin and its rocky extremes. Evolution Valley is a paradise of green compared to the rock-bound lakes further South. Take your time here. Savor it. Make it last. You'll be leaving soon, and in a few days, all this will seem like delirious dream. The gradient is gentle until after you splash across Evolution Creek at the Valley's lowest end. After that the drop is quick and steep into Goddard Canyon. So yeah, it's warm, but water's never far away, and at the end of the narrow canyon lies the Piute Creek Crossing, which is like a water park, only with no lines and cleaner air. Since I only seem to hit the next segment in the heat of the day, I never seem to come away with pleasant memories of it, but the stretch leading to the bottom of the valley can be devilishly hot. But hey, at least you're going downhill. And this alone, rates this an easier direction for this segment of the John Muir Trail.
