<P> The Southwest has the worst droughts; one is thought to have lasted over 500 years and to have decimated the Anasazi people . Large stretches of desert shrub in the west can fuel the spreads of wildfires . Although severe drought is rare, it has occasionally caused some major problems, such as those during the Dust Bowl (1931--1942), which coincided with the Great Depression . Farmland failed throughout the Plains, entire regions were virtually depopulated, and dust storms ravaged the land . More recently, the western US experienced widespread drought from 1999 to 2004 . </P> <P> In terms of deaths from heatwaves, 7,415 losses occurred between 1999 and 2010, a mean of 618 per year . A disproportionate number of men, a full 68% of deaths, versus women have been affected . The highest yearly total of heat - related deaths during that time frame was in 1999 . The lowest was in 2004 . In terms of deaths caused by waves of cold temperatures, the same gender inequality exists; 66% of hypothermia - related deaths in 2002 were of males . From 1979 to 2002, 16,555 deaths occurred due to exposure to excessive cold temperatures, a mean of 689 per year . </P>

Which states are in the desert climate zone