According to NOAA scientists, 2011 was a record-breaking year for climate extremes, as much of the United States faced historic levels of heat, precipitation, flooding and severe weather, while La Niña events at both ends of the year impacted weather patterns at home and around the world.
NOAA’s annual analysis of U.S. and global conditions, conducted by scientists at NOAA’s National Climatic Data Center, reports that the average temperature for the contiguous U.S. was 53.8 degrees F, 1.0 degree F above the 20th century average, making it the 23rd warmest year on record. Precipitation across the nation averaged near normal, masking record-breaking extremes in both drought and precipitation.
On a global scale, La Niña events helped keep the average global temperature below recent trends. As a result, 2011 tied with 1997 for the 11th warmest year on record. It was the second coolest year of the 21st century to date, and tied with the second warmest year of the 20th century.