Preliminary data computed from the Palmer Drought Severity Index shows that 54.6 percent of the contiguous 48 states was in drought at the end of June, the highest percentage since December 1956, and the sixth-highest peak percentage on record.

FORBES: The Great American Drought: Climate Change? The New Dust Bowl?

Our list was compiled with the help of Bert Sperling, who created his Sperling Drought Index by combining a variety of data and indices from the National Climatic Data Center.

FORBES: Magazine Article