Days are usually quite pleasant up at the ranch. Mornings and Evenings are the nicest, with temperatures in the '70s. During the day, it can get a bit hot and sunny. Bring a lot of sunscreen. Also bug repellent is a really good idea--there are not that many mosquitoes but not nice to get a lot of bites!
The winds can come up quickly and take your tent away in a matter of minutes. So, check the weather and baton down the hatches if the forecast calls for scattered showers or storms.
Evenings are chilly--bring warm clothes and nice sleeping bags!!!