A few days of unusually cold weather in the U.S. and Canada aren't a sign that a century-or-more trend of rising global surface temperatures has reversed itself. In fact, the cold wasn't even all that widespread for the Northern Hemisphere.

From reindeer to regional temperature patterns, from sea ice age to Greenland surface melt, the Arctic Report Card is a yearly assessment of the Arctic's physical and biological systems and how they are changing. This collection of visual highlights from the 2013 report is a story of the Arctic in pictures.

Since the mid-1960s, the Arctic has warmed about 3.6°F (2.0°C)—more than double the amount of warming in lower latitudes. In 2012 (the last complete calendar year available at the time scientists began working on the 2013 Arctic Report Card), the annual average temperature was the sixth warmest on record.

October in Alaska this year was more like September, with warmth and rain in place of autumn chill and snow. Wind anomalies related to unusual pressure patterns conspired to bring a steady stream of warm, wet air from southerly latitudes into Alaska.

August 2013 came and went without a single Atlantic hurricane. That's unusual, but by no means unprecedented.

flooded houses on Breezy Point following Hurricane Sandy

Understanding how extreme events in 2012 were influenced—or not—by human-caused climate change

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