Around this time of the year, I wouldn't go to California or Florida because of the weather.
Ceiling and visibility can be awful near the West coast (sometimes it takes a whole day to dissipate and starts again the next morning), and thunderstorms/rain might ruin your day on the East coast.
Some places in Texas also get their share of thunderstorms and bad weather around the summer.
If time is really important, and in this case I believe it is otherwise you'll loose on accomodation what you gained on lease rates, I would avoid the coasts and go to a dry place like Arizona. Phoenix sounds perfect to me.