The drought footprint cover 63% of the contiguous states during the hottest month in American history. It's the hottest 12 month stretch (August 2011-July 2012) on record for the lower 48, making it the fourth consecutive month to set a new record (i.e. old record was July 2011-June 2012).The biggest difference from other hot months is the nighttime temperature have been exceptionally high. The most current drought monitor map can be found at the University of Nebraske website.
Via Seth Dixon