The past week has brought a searing heat wave to the deserts of the southwestern United States. Conditions in Death Valley, California, have been especially hot. The daily high temperature has been in the 120s every day since June 15. With afternoon dew points in the 20s, the resulting relative humidity values have been as low as 3%.
Death Valley in a heat wave is other-worldly. The sky is whitish-blue and cloudless. Wind is almost nonexistent and then occasionally quite gusty. Dust devils grow to enormous height. There is very little sound except for the occasional buzz of an insect wing. Human life is 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 slightly during the second half of summer.