Welcome to ATP Laurie.
I grow all my clematis in full sun. Clematis like their vines, that is their leaves, in the sun but the roots like to stay cool. The best way to accomplish that is with a nice thick mulch to shade those roots and to help keep them moist. In fact I would say that mulch is a must do in your hot climate.
I agree with Sharon that you should keep them well watered.
