The past week brought a searing heat wave to the deserts of the Southwest United States.
Conditions in Death Valley, Calif., have been especially other-worldly. For several days last week, afternoon temperatures in the mid to upper 120s combined with dew points in the 20s resulted in relative humidity values as low as 3 percent. The sky was whitish-blue and cloudless. Wind was almost non-existent. There is very little sound except for the occasional buzz of an insect wing, although a few creatures manage to live there in the sunshine in summer.
Such conditions make human life a shaky endeavor for even just a few hours without water and shade. The hottest temperatures across the Desert Southwest are often during late June or early July. Once these deserts become so hot, thermal low pressure starts to draw air in from the Pacific Ocean, cooling temperatures during the second half of the summer.
