105 F and very humid. But worth it. Just beware that signage is sparse at places and it's possible to get off the main trail when it goes through one of the cemeteries.
I also recommend hiking Mt. Hiei or walking along the river - just to take in the ambience. It's called the Philosopher's path because it was a favorite place for many Nobel prize winners to go to relax and think. The area of the outdoor restaurants on stilts is fun, as is the park area further upstream where the river is split.
From there you can see Shimogamo jinja.
Other cool places include Go sho (Emporer's palace), the rock gardens (Ryoan-ji), ginkaku-ji etc..
Just too many places to list.