I spent July and August of 2013 in Las Vegas, it was consistently running between 115-118F during the day.
I had both ACs running full time (15,000 btu living area, and 13,500 btu bedroom), and I had to install aluminum backed windshield shades in all the windows to keep the inside tolerable.
It still got up to about 78-80F inside during the day, but at night it went down to 70F, which was what I set the thermostats to.
I must admit, I only have single pane windows, but the windshield shades made all the difference. Without them, you couldn't sit near a window, even with the blinds down.
Sheff
