01/22/2012 04:13 pm ET Updated Dec 06, 2017

2011: Second Coolest Year of Past 11

The official climate report has been issued by NOAA, and while 2011 was warmer than average globally, the year was the second coolest year of the relatively young 21st century.

In a separate release, NOAA updated the number of record-breaking billion-dollar-plus weather disasters from 12 to 14.

Two separate La Nina events -- one lingering through spring and a second beginning in the fall -- helped to keep global temperatures cooler than it would otherwise have been, according to NOAA scientists. Global temperatures were 1.0 degrees Fahrenheit above the 20th century average, making 2011 the 11th warmest year since records began (1880).

In the United States, 2011 was the 23rd warmest year on record, with near-normal precipitation. The precipitation stats are a little misleading since that represents an average of the two extremes of record-breaking precipitation in some areas from the Midwest and Northeast and record-breaking drought in parts of the South. This is something I talked about recently (Record-Breaking Warmth, Precipitation, and Drought Highlight 2011 Weather Extremes)

La Nina is a cooling of sea-surface temperatures in the equatorial Pacific that tends to have an overall cooling effect on global temperatures and influence global weather patterns.


The weather patterns have included a plethora of dramatic weather events in recent months, and additional information has prompted NOAA to add two weather disasters to the already record-breaking number of 12 for the 2011 calendar year. The newly included disasters include the flooding from the remnants of Tropical Storm Lee in the Northeastern U.S. and parts of the mid-Atlantic region.

Lee followed closely on the hills of the devastating Hurricane Irene in early September.

Also added to the list was an outbreak of damaging thunderstorms and tornadoes in the Rockies and Midwest in July.

I expected that the number of billion-dollar weather disasters would be increased to 14, but I thought that it would have included the record-breaking October snowstorm in the Northeast and northern mid-Atlantic region. That storm has not -- at least as of yet -- been added to this official list.