Source here. (click on image to enlarge)
This chart represents the 15 years (180 months), starting May 1, 1997 and ending April 30, 2011. Per the latest NOAA/NCDC U.S. temperature data records, the 12-month period ending April was the 5th coldest April-ending period for the last 15 years. In terms of a single month, April 2011 was 79th coldest April in the past 117 years.
The per century cooling trend of this period, a minus 3.2°F, took place in spite of the huge warmth produced by two large El Niño events during this 15-year span: 1997-1998 and 2009-2010.
For the 10-year period ending April 2011, the cooling trend accelerates to a very significant minus 12.9°F per century rate - again, per the updated NOAA/NCDC temperature records. (click on image to enlarge)
At some point, U.S. continental warming will resume, but the extended decade-long plus global cooling trend persists, contradicting the experts. None of the IPCC climate models, nor "consensus" experts predicted this cooling trend for the continental U.S.
Additional modern temperature charts. Historical temperature charts.