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Posted at 10:30 AM ET, 08/09/2011

July: most extreme and 4th warmest in US; Oklahoma hottest ever state average temperature

Climate Extremes Index during July. July 2011 was the higest on record. View bigger. (NOAA)
NOAA released the July “State of the Climate” update for the U.S., and, no surprise, reported blistering heat torched large parts of the country. The average temperature of 77 was the fourth warmest since 1895. Amazingly, Oklahoma’s average July temperature was 88.9 degrees - the warmest to occur in any state during any month on record.

But July was not only scorching hot. July’s Climate Extremes Index, which examines the percentage of the U.S. impacted by a full range of extreme weather conditions, was the highest on record for the month (since 1910). Thirty seven percent of the country contended with extreme weather. The extreme July - for all extreme weather classifications - follows the most extreme spring for precipitation .

The primary factors which led to such an extreme July were: extreme warm minimum temperatures, extreme wetness in the northern plains and western Great Lakes, extreme warm high temperatures, and extreme drought in the south central U.S. through Gulf Coast.

Temperatures compared to average during July 2011 (NOAA)
In Oklahoma, the heat and drought were a punishing double whammy. In a vicious cycle, the dry soil intensified the heat and the heat dried out the soil. The result: heat unprecendented in any state at any time. The Oklahoma Climatological Survey unveiled this news dramatically

Grover Cleveland was serving his second term as President in 1895. Victoria was the Queen of England and Will Rogers was still a teenager. It is also the year that statewide average temperature records begin for the United States. There have been 1399 months pass by since 1895. Multiply that number by 48 and you have 67,152 months of temperature records for the contiguous states. How hot was it in Oklahoma last month? Of those statewide average temperature records for the 48 states, none has been hotter than July 2011 in Oklahoma.

Some other highlights from NOAA’s July report:

Close to Home comic by John McPherson
* Texas also had its warmest month on record, averaging 87.1 degrees.
* 41 out of the lower 48 states had temperatures above average , much above average or record-warmest. Areas west of the Rockies had near to below average temperratures.
* The South climate region - which encompasses Arkansas, Kansas, Louisiana, Mississippi, Oklahoma and Texas, had its warmest calendar month on record - which was warmer than any other region’s warmest month.
* Precipitation overall was 0.32” below average with large regional variability.
* Exceptional drought covered the largest area in its 12-year history, including 75 percent of Texas. Moderate to exceptional drought covered 100 percent of Oklahoma.
* Wetter than average conditions occurred along the central Gulf Coast, West Coast, and parts of the upper Midwest and Northern Plains.

For additional information about July, read NOAA’s State of the Climate Report.

By  |  10:30 AM ET, 08/09/2011

Categories:  U.S. Weather, Latest

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