HOTTEST SUMMER NIGHTS

The Worst Summer Ever? 'Dark Side of Climate Change' Seen in Record Setting Night-time Temperatures; Special Risk Seen to Elderly, Low-Income Population…Records Set in AL, AZ, AR, CT, DE, FL, GA, IL, IN, IA, KS, KY, LA, ME, MD, MA, MI, MN, MS, MO, NH, NJ, NM, NY, NC, ND, OH, OK, PA, RI, SC, SD, TN, TX, VA, WV, and WI.
September 16, 2010 (Natural Resources Defense Council)

"…[T]here is growing concern about the largely ignored pattern of record-setting nighttime temperatures, which pose special dangers to elderly and low-income Americans who are more dependent on overnight cooling during the hottest months.

"[T]he Natural Resources Defense Council (NRDC) [found]…[1] At nearly one of four weather stations in the contiguous United States -- 278 out of 1,218 -- the average nighttime low temperatures for June, July and August 2010 were hotter than at any time since 1895…[2] 40 percent [of the 513 weather stations east of the Mississippi] reported their hottest average nighttime low temperatures on record and more than 80 percent reported average nighttime low temperatures among their five hottest on record in summer 2010…[3] More than half of all U.S. weathers stations recorded average nighttime low temperatures among their five hottest on record…[4] Record nighttime temperatures were set at stations in 37 states…"

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"Nighttime temperatures are more sensitive to the buildup of heat-trapping pollution in the atmosphere than daytime temperatures because increases in atmospheric aerosols and cloud cover have counteracted some of the warming effect of greenhouse gases during the day…"

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"The NRDC analysis [also found]…[1] In Maryland, 12 of the 16 stations in the Historical Climatology Network reported their hottest average nighttime low temperatures on record in summer 2010. All 16 Maryland stations reported average nighttime low temperatures among their five hottest on record…[2] In Florida, nearly all -- 21 of 22 -- weather stations reported average nighttime low temperatures among their five hottest…[3] The Midwest also experienced very warm nighttime temperatures. In Illinois and Indiana, 92 percent and 86 percent of the stations, respectively, reported average nighttime low temperatures among their five hottest…[4] The Western United States was not as hot as the Eastern half of the country. Nonetheless, seven stations in Arizona reported average temperatures for this summer among their five hottest on record, and 11 stations in New Mexico reported average nighttime low temperatures among their five hottest."

[From the NRDC analysis:] “Record-high temperatures are not the only weather extremes we have seen in 2010. Because the atmosphere can hold more moisture as it warms, there is more rapid evaporation when it is dry and more intense rainfall when it is wet. The result is an increase in severe droughts and floods. As we have seen in Russia, Pakistan, China, and the United States, the results have been tragic. Russia has seen hundreds of wildfires and thousands of deaths in Moscow during its worst heat wave on record. In Pakistan more than a thousand people have been killed, and a million more displaced by floods. Flooding this year has also killed more than a thousand people in China, and more than 50 in Iowa and Tennessee.”