I have only been once, to Mad Cow wall, a couple if weeks ago. It was about 86f that day, wall was in the shade and it was chilly. I imagine up to low 90s should be fine in the shade. Fyi, I am in El Paso, TX. Far enough away to need to make it a 2day trip.
Last Chance isn’t bad if you move walls throughout the day. Tombstone and solstice get good shade in the morning then Tornado, Fossil, and breakfast will get shade later on in the day. I usually head out there on a Friday and camp until Sunday then leave Sunday afternoon or evening. Always looking for people to join. I don’t think I’ll make it back out until later June. I’ll be coming from Midland. If that kind of weekend trip would be possible I would love to meet up!