In the semi-arid Horn of Africa, rain comes in two seasons: the “short rains” of October-December and the “long rains” of March-June. In late 2010 and early 2011, both rainy seasons brought scant rain to the region, which led devastating drought across several countries in 2011. In Somalia, the drought escalated to famine.

In 2010, global temperatures were marked by near-record warmth and strong natural variability. This is the first in a series of posts highlighting findings from the "State of the Climate in 2010" report.

Two natural climate patterns, the Arctic Oscillation and the El Niño-Southern Oscillation, had strong influences on the patterns of unusually warm and unusually cool spots worldwide in early and late 2010.

A pattern of unusually warm and cold spots alternated around high northern latitudes in 2010—a classic sign of the negative phase of the Arctic Oscillation.

Between January and April 2010, temperatures in the Pacific were under the warming influence of a fading El Niño episode. Meanwhile, higher latitudes of the Northern Hemisphere were dominated by a strong negative phase of the Arctic Oscillation.

In early 2010, water temperatures in the eastern tropical Pacific were warmer than average, but a summertime reversal cooled the region off over the rest of the year.

Image highlights form the 2011 State of the Climate report.

2011 State of the Climate Report editor Jessica Blunden talks about the process of creating and editing the report.

In the Arctic, an ocean is surrounded by continents, while Antarctica is continent surrounded by oceans. These differences in the arrangement of land and water contribute to differences in each polar region’s climate, oceanic and atmospheric circulation patterns, and seasonal and long-term sea ice patterns.

Starting in July, when you hear that a day was hotter, or colder, or rainier than normal, that normal will be a little different from what it was in the past.