The average temperature for the contiguous U.S. during July was 77.6°F, 3.3°F above the 20th
century average, marking the warmest July and all-time warmest month on
record for the nation in a period of record that dates back to 1895.
The previous warmest July for the nation was July 1936, when the average U.S. temperature was 77.4°F.
Warmer-than-average conditions engulfed much of the contiguous U.S. during July, with the largest temperature departures from the 20th century average occurring across much of the Plains states, through the Midwest, and along the Eastern Seaboard. Virginia had its warmest July on record, with a statewide temperature 4.0°F above average. In total, 32 states had July temperatures among its ten warmest, with seven states having their second warmest July on record.
An active storm pattern in the Southwest contributed to California having its fifth wettest July on record and Nevada having its eighth wettest. Wetter-than-average conditions were also observed through the rest of the Southwest, along the western Gulf Coast, and into the Ohio Valley, where West Virginia had its tenth wettest July.
According to the July 31, 2012 U.S. Drought Monitor (USDM),
62.9 percent of the contiguous U.S. was experiencing moderate to
exceptional drought at the end of July. This is an increase of about
6.9 percent compared to the end of June. The maximum value of 63.9
percent reached on July 24 is a record in the 13-year history of the
USDM. The percent area of the country in the worst drought categories
(extreme to exceptional
drought) doubled, from 10 percent last month to 22 percent this month.
The extreme dryness and above-average evapotranspiration due to
excessive heat devastated crops and livestock from the Great Plains to
Midwest.
According to the Palmer Drought Severity Index, whose record spans the 20th
century, about 57 percent of the contiguous U.S. was experiencing
moderate-to-extreme drought. The last time drought was this extensive
was in December 1956 when about 58 percent of the nation was in
moderate-to-extreme drought.
The warm and dry conditions over a large portion of the country
were associated with ideal wildfire conditions. Over 2 million acres
were burned nationwide during July due to wildfires, nearly half a million acres above average, and the fourth most in the 13-year period of record.