http://www.washingtonpost.com/blogs/capital-weather-gang/post/us-completes-warmest-12-month-period-of-record/2012/05/08/gIQAgsmmAU_blog.html

U.S. completes warmest 12-month period in 117 years

May 2011 to April 12 ranked as the warmest 12-month stretch over the U.S. since records began in 1895 (NOAA NCDC)

As far back as records go (1895), never has the U.S. strung together 12 straight months warmer than May 2011 to April 2012 according to new data released today by NOAA’s National Climatic Data Center.

The record-setting 12-month period edged out November 1999-October 2000, the 2nd warmest 12-month period, by 0.1°F. The average temperature was 2.8 degrees F above the 20th century average.

As warm as it’s been, it’s no surprise that the calendar year 2012 (spanning January to April) is off to a record warm start, 5.4 degrees F above average across the Lower 48. Twenty-six states east of the Rockies logged their warmest start to the year on record, including Virginia and Maryland.