Watering plants in pots in full sun?

I have two daisy trees in pots that receive a lot of sun. And i mean a lot of sun. They are out on the pool deck and they receive no shade at all until the sun sets. We've been having some hot weather, getting into the high 90's and the 100-108's. Its a dry climate here in the San Joaquin Valley. Do I need to be watering these plants every day? BTW, I also have daylilys in the pots. The plants look horrible, they are wilted. I was watering them every day for a while, but they weren't doing any better. Any suggestions?