The all-red map tells the story.
According to the National Oceanic and Atmospheric Administration:
"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."
Of course, the fact that it's been really hot isn't going to be a big surprise. Nor is the fact that much of the nation is gripped in an awful drought.
As NPR's Christopher Joyce has reported, "among scientists, there's a growing view that these latest heat waves are indeed a result of climate change."
Update at 1:15 p.m. ET. Another Way Of Looking At The Map.
NOAA has also produced a map showing where last month's temperatures were significantly different from the 1981-2010 average. The darker the color, the more extreme (to the upside) the temperatures were.
From NOAA: This map "shows where July 2012 temperatures were different from the 1981-2010 average across the contiguous United States. Shades of red indicate above-average temperatures and shades of blue indicate below-average temperatures the darker the color, the more unusual the temperature difference."
From NOAA: This map "shows where July 2012 temperatures were different from the 1981-2010 average across the contiguous United States. Shades of red indicate above-average temperatures and shades of blue indicate below-average temperatures the darker the color, the more unusual the temperature difference." noaa.gov
Update at 1 p.m. ET. Where July Ranks, State-By-State.
A national average is one thing, but what about where you were last month? NOAA has a webpage showing how last month stands compared to other months of July in each of the "lower 48" states.
July 2012 ranks as the hottest July on record in two states, North Dakota and Virginia.
July 2012 makes it into the top 10 hottest Julys on record in 30 other states:
Leaving 16 states where July 2012 wasn't at least a top 10, temperature-wise: