National Overview - May 2012
Warmest 12-month consecutive periods of the CONUS

« National Overview - May 2012


Warmest 12-month consecutive periods of the CONUS

These are the warmest 12-month periods on record for the contiguous United States. During the June 2011-May 2012 period, each of the 12 months ranked among the warmest third of their historical distribution for the first time in the 1895-present record. The odds of this occurring randomly is 1 in 531,441.


Warmest 12 months

Rank Consecutive 12-month Period Temperature Departure
(from 20th Century Average)
Warmest June 2011 — May 2012* +3.18°F
2 Warmest May 2011 – April 2012* +2.83°F
3rd Warmest November 1999 – October 2000 +2.70°F
4th Warmest October 1999 – September 2000 +2.65°F
5th Warmest April 2011 – March 2012* +2.61°F
6th Warmest September 2005 – August 2006 +2.56°F
7th Warmest August 2005 – July 2006 +2.54°F
  September 1999 – August 2000 +2.54°F
9th Warmest July 1999 – June 2000 +2.51°F
10th Warmest June 1999 – May 2000 +2.46°F
  August 1999 – July 2000 +2.46°F

* – Preliminary Data