News & Features

La Niña—the cool phase of the El Niño-Southern Oscillation—dominated the Pacific Ocean at the start of 2011, subsided in summer, and returned in fall.

The lead character in the 2011 climate story was La Niña—the cool phase of the El Niño-Southern Oscillation—which chilled the central and eastern tropical Pacific at both the start and the end of the year. These natural cooling events have a long reach: many of the big climate events of 2011, including famine-inducing drought in East Africa, an above-average hurricane season in the Atlantic, and record rainfall in many parts of Australia, are common “side effects” of La Niña.

Each year, following months of number crunching and fact-checking, hundreds of climate and earth scientists contribute to a global-scale evaluation of climate and environmental conditions over the previous year. This analysis--our planet's annual check up--is known as the State of the Climate report. Highlights of the 2011 State of the Climate report include wild weather extremes, a double-dip La Niña, and continued evidence of long-term climate warming.

Scorching temperatures during the second half of June 2012 broke or tied over 170 all-time temperature records in cities across America.

NOAA's 2012 hurricane outlook favors a slightly below average number and strength of storms in the central Pacific basin and a near-average season in both the Eastern Pacific and Atlantic basins.

In late-April 2011, an unusual, post-winter Nor’easter brought much-needed rain the Northeast United States.

Spring storms across Europe and the Mediterranean Sea finally swept away a high pressure system that had been fostering increasingly dry conditions over the Horn of Africa in early 2011.

The average global temperature (land and ocean) for May 2012 was the second warmest May temperature since recordkeeping began in 1880, and the temperature over land surfaces was the warmest on record for May. May 2012 also marks the 327th consecutive month with a global temperature above the 20th-century average.

The average temperature for the United States during May was more than 3 degrees F above the long-term average, making it the second warmest May on record. The month's high temperatures also contributed to the warmest spring, warmest year-to-date, and warmest 12-month period the nation has ever experienced since record keeping began in 1895.

Deke Arndt, Chief of the Climate Monitoring Branch at NOAA’s National Climatic Data Center talks about the unusual heat in May 2012.