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NOAA: 2011 a year of climate extremes

According to the National Oceanic and Atmospheric Administration (NOAA), 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.

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.

The agency said that warmer-than-normal temperatures were anchored across the South, Mid-Atlantic and the Northeast. Delaware had its warmest year on record, while Texas had its second warmest year on record.

Despite a “near normal” national precipitation average, regional precipitation outcomes varied wildly. Texas, ravaged by exceptional drought for most of 2011, had its driest year on record. In contrast, seven states in the Ohio Valley and Northeast — Connecticut, Indiana, Kentucky, New Jersey, New York, Ohio, and Pennsylvania — had their wettest year on record.

On a global scale, La Niña events helped keep the average global temperature below recent trends, said the agency. 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.

The 2011 global combined land and ocean surface temperature was 0.92 degrees F above the 20th century average of 57.0 degrees F. This marks the 35th consecutive year, since 1976, that the yearly global temperature was above average. The warmest years on record were 2010 and 2005, which were 1.15 degrees F above average.

The 2011 globally-averaged precipitation over land was the second wettest year on record, behind 2010. Precipitation varied greatly across the globe. La Niña contributed to severe drought in the Horn of Africa and to Australia’s third wettest year in its 112-year period of record.

Source: NOAA