I have a rhododendron, planted in full sun, on the west side of my garden. It get shade late in the afternoon.
The leaves seem to be curling and turning brown. I hope you can see from the attached pictures.
Buds have developed, and I water twice a week , more if needed.
Whats wrong with my Rhododendron?
Too much sun. Provide some shade starting around 11am to 12pm. Your sun and mine are too strong in the summer and they cannot take much of it. In the northern states however, you can get by full sun conditions but down here, they will suffer from sunscald. You can build a contraption to provide bright shade full time until cooler temps arrive. Or get 35% shade cloth. Or transplant it (I would leave that for later, when it has gone dormant).
I had a similar problem with a hydrangea whose protecting Crape Myrtle lost some limbs in mid summer due to a storm. I shaded it with sticks and cartons until Fall arrived. It was flimsy, did the job and I sure had to reconstruct it again a few times due to winds but hey, it worked.
Kind of figured it was that. I will put up something to shade it, some shade cloth for the rest of the summer, then move it. This is the first Rhodie I have grown here in my new home in Ga.
So its an adventure in learning new things.
I will second what the other poster said. Your poor Rhodie is getting scorched. The advice from Luis is good.