U.S. experiences warmest 12-month period on record, again – One-in-1.6 million event
[UPDATE: Probably not as unlikely as 1-in-1.6 million; more like 1-in-134000.] By Dr. Jeff Masters
9 July 2012 Thanks in part to the historic heat wave that demolished thousands of high temperature records at the end of June, temperatures in the contiguous U.S. were the warmest on record over the past twelve months and for the year-to-date period of January – June, said NOAA’s National Climatic Data Center (NCDC) on Monday. June 2012 was the 14th warmest June on record, so was not as extreme overall as March 2012 (first warmest March on record), April (third warmest April), or May (second warmest May.) However, temperatures were warm enough in June to set a new U.S. record for hottest 12-month period for the third straight month, narrowly eclipsing the record set just the previous month. The past thirteen months have featured America’s 2nd warmest summer (in 2011), 4th warmest winter, and warmest spring on record. Twenty-six states were record warm for the 12-month period, and an additional sixteen states were top-ten warm. The year-to-date period of January – June was the warmest on record by an unusually large margin–1.2°F. U.S. heat over the past 13 months: a one in 1.6 million event Each of the 13 months from June 2011 through June 2012 ranked among the warmest third of their historical distribution for the first time in the 1895 – present record. According to NCDC, the odds of this occurring randomly during any particular month are 1 in 1,594,323. Thus, we should only see one more 13-month period so warm between now and 124,652 AD–assuming the climate is staying the same as it did during the past 118 years. These are ridiculously long odds, and it is highly unlikely that the extremity of the heat during the past 13 months could have occurred without a warming climate. Some critics have claimed that recent record warm temperatures measured in the U.S. are due to poor siting of a number of measurement stations. Even if true (and the best science we have says that these stations were actually reporting temperatures that were too cool), there is no way that measurement errors can account for the huge margin by which U.S. temperature records have been crushed during the past 12-month and 6-month periods. […]
