Melons do love warm weather but I suspect your climate in Arizona is too hot for even melons during the summer season. Powdery mildew often attacks after overhead watering so try to keep the foliage dry. Blossoms need to be pollinated to develop fruit and when the heat is excessive the bees and other pollinators are not out in full force. The solution may be to wait until the weather starts to cool in the fall or to plant in very early spring before the weather becomes too hot. Your best advice on planting in your area is going to be a local garden club or master gardener. Ask at a local nursery on how to contact garden clubs in your area. Every climate is different and the successful gardeners in your area are the ones that understand best what varieties and what planting schedules work best.  Don't give up as with just a few trial and error experiments you can have a great time gardening even in the desert climate. Keep growing, Marianne Binetti