May

Average high: 88.8°F (31.6°C)
Average low: 57.4°F (14.1°C)
Relative humidity at 5 am: 34%
Relative humidity at 5 pm: 13%
Normal rainfall: .15” (3.8mm)

May will likely see the first day over 100°F (38°F) in the desert; most days will be clear, dry and hot. Many animals, humans included, begin to retreat to the mountains, where balmy days and cold but not freezing nights beckon.

Flora
Many species of Cactaceae bloom nocturnally, including saguaros, senitas, organ pipes, and queens-of-the-night, also known as night-blooming cereus. Delicate lavender blossoms open on desert ironwood and smoke trees. Desert spoon and soaptree yuccas put up tall, woody bloomstalks with white flowerettes; desert spoon is dioecious, with male or female flowers. Many red, trumpet-shaped flowers are blooming in mountain canyons as hummingbirds become more numerous and continue breeding; among the most spectucular blossoms are those of the coral bean.

Fauna
Female nectar-feeding bats, many of which are pregnant, migrate from Mexico into desert areas where nocturnally blooming plants are flowering. The two species are Mexican long-tongued and lesser long-nosed, the latter of which are endangered; they give birth in colonial maternity caves. Gila monster eggs, laid ten months ago, begin to hatch; the young lizards are perfectly formed miniature versions of their venomous parents and immediately fend for themselves. In mountain canyons, red-spotted toads are mating, filling the nights with their loud trills.

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