The Arizona-Sonora Desert Museum has a wonderful program called "Cool Summer Nights" and it is designed as a way for visitors to enjoy the museum during the cooler evening hours. It is on Saturday nights. Not only can you see special programs and hear docent talks, you can also enjoy some of the regular exhibits like, for instance, the Hummingbird House where you get up close and personal with these tiny beauties.
I'm a transplanted New Yorker who loves the Tucson climate. On New Year's Day I have a bit of fun calling my (snowbound) east coast friends to announce that I'm drinking coffee while sitting on my patio. (: