However we also have a little feature we lovingly call "Valley Fever" which is a fungus, spread mostly by dust storms. As more Midwestern folks immigrated here, and the Snowbirds set up shop, they all wanted traditional lawns, trees, and golf courses, just like "back home". So by the 1980s-1990s, Phoenix was barely differentiated from Chicago or Kansas in terms of front yards.
Now, those gardens definitely kept things cool in a local area. They needed things like flood-irrigation, so deep water often covers lawns. Deciduous or even evergreen trees can afford a lot of shade where you really, really need it. Unfortunately, monsoon microbursts often topple those kinds of trees, which have shallow roots in impoverished, sandy soils.
Ironically, due to lack of water, and Greta Thunberg, we're reverting to desert landscapes (called xeriscape) and so the new urban domestic hotness here is to install little "drip irrigation" tubes, palo verde, cactus, succulents, yucca, etc. Needless to say, they don't provide enough shade, and the humidity stays quite low.
Phoenicians today are clamoring for more artificial shelter and shade. Bus stops here are works of art with elaborate means of warding off the daytime heat. The city centers are still "heat islands" with murderous temperature increases during summertime ("summertime" in Phoenix lasts from March through October...)