Organ Pipe Cactus National Monument, an International Biosphere Reserve, contains a thriving community of plants and animals, and human stories echo throughout this desert preserve, chronicling thousands of years of desert living. Scenic drives, wilderness hikes, and nights of camping reveal a living desert that thrives. Summer months are hot, with temperatures exceeding 100F, while winter months are milder, with temperatures in the 70s and overnight lows in the 40s.