Northern Hemisphere Snow Cover Extent

The Northern Hemisphere snow cover extent for April 2023 was 30.27 million square kilometers (11.69 million square miles), which was 340,000 square kilometers (130,000 square miles) above the 1991–2020 average.

This April was a near-average April snow cover extent for the Northern Hemisphere.

The North America and Greenland snow cover extent for April was 13.92 million square kilometers (5.37 million square miles), which was 750,000 square kilometers (290,000 square miles) above the 1991–2020 average. This was the 16th-largest April snow cover extent for North America on record.

Above-average April snow cover extent was observed across much of western North America, the midwestern U.S., and central–east Canada. The northeastern U.S. experienced below-average April snow cover extent.

Snow cover extent over Eurasia in April was 16.35 million square kilometers (6.31 million square miles), which was 410,000 square kilometers (160,000 square miles) below the 1991–2020 average. This was the 15th-smallest April Eurasian snow cover extent on record.

Across Eurasia, parts of western Europe, Turkey, southwestern Russia, and western Mongolia had below-average snow cover extent this month. Parts of Scandinavia, southeastern Russia, and central China had above-average extent for April.

Sea Ice Extent

The sea ice extent data for the Arctic and Antarctic are provided by the National Snow and Ice Data Center (NSIDC) and are measured from passive microwave instruments onboard NOAA Satellites. The sea ice extent period of record is from 1979–2023 for a total of 45 years.

Globally, April saw the third-smallest sea ice extent on record. Only the Aprils of 2019 and 2017 saw smaller sea ice extents.

The Arctic sea ice extent for April 2023 tied with 2004 as the 11th smallest in the satellite record at 13.99 million square kilometers (5.40 million square miles). This was 330,000 square kilometers (130,000 square miles) below the 1991–2020 average.

Sea ice extent was below average in Baffin Bay, the Barents and Bering Seas the Gulf of Saint Lawrence, and the Sea of Okhotsk. The Sea of Japan and Greenland Sea had slightly above-average sea ice extent this April.

The April 2023 Antarctic sea ice extent was 5.49 million square kilometers (2.12 million square miles), or 1.46 million square kilometers (560,000 square miles) below the 1991–2020 average. This ranks as the third-smallest April extent on record.