July Hottest Month on Record in U.S.—Warming and Drought to Blame?
Lower 48 sweltered due to widespread heat ridge, expert says.
The lower 48 U.S. states experienced an average July temperature of 77.6 degrees Fahrenheit (25.3 degrees Celsius).
That's about 3.3 degrees (1.8 degrees Celsius) above the 20th-century average and the highest July average since record-keeping began in 1895, according to a report released August 8 by the U.S. National Oceanic and Atmospheric Administration (NOAA).
For 2012, July wasn't an anomaly, either. Taken together, the first seven months of the year have been, on average, the warmest January-to-July period on record in the contiguous U.S. states.
Drought conditions in more than 60 percent of the country helped keep temperatures high, explained Kevin Trenberth, a senior scientist at the Boulder, Colorado-based National Center for Atmospheric Research.
"If it is wet, it tends to be