Organ Pipe Cactus National Monument, view from Dripping Springs on the Puerto Blanco Drive. The summer weather is always hot and often humid, but clear days are common in between periods of thunderstorms. That this is the summer rainy season is evident from the lush green of the vegetation. (Hey - it's a desert - this is as green as it gets.) Though you can see some palo verdes on the hill in the midground, most of them are concentrated in the drainages and the saguaros are also more common in the valley than on the hillsides. For this reason this area could just as well be classified in the Lower Colorado River Valley subdivision of the Sonoran Desert.