More than a week of torrential rain in mid-September 2011 caused deadly floods across Sichuan, Shannxi, and Henan provinces in China.

Seasonal precipitation patterns across the globe showed large differences from average in 2011, with several areas receiving heavy rains during more than one season of the La Niña-influenced year.

A year-long La Niña contributed to dramatic variability in seasonal temperature patterns in 2011.

In the 2011 Arctic Report Card, scientists report that the bright white surface of the Greenland Ice Sheet has grown less reflective. The darker surface absorbs more sunlight, accelerating melting.

Climate forecasters often describe the Arctic Oscillation as the “wild card” of the winter forecast. So far in 2011, the Arctic Oscillation has been in its positive phase, playing the card that favors a milder winter in the eastern United States.

NOAA’s official Winter Outlook for 2011–2012 is unlikely to please many residents of either the still-soggy Missouri River Basin—which experienced historic flooding this past spring and summer—or the parched south-central United States, where severe to exceptional drought has been in place since spring.

The U.S. had its fourth warmest winter on record. In this episode of ClimateCast, NOAA’s Deke Arndt recaps the 2011-2012 winter.  

Phytoplankton productivity has increased 20 percent over the past decade as sea ice extent declines and more open water habitat is available.

Satellite observations show that as the Arctic tundra has grown warmer in the past three decades, it has also grown “greener.”

On December 1, NOAA released its annual Arctic Report Card. Like a yearly check-up at the doctor's office, the report summarizes conditions in the Arctic atmosphere, ocean, and on land.