Northern Hemisphere Snow Cover Extent

The Northern Hemisphere snow cover extent for August 2024 was 2.61 million square kilometers (1.01 million square miles), which was near average; 70,000 square kilometers (30,000 square miles) below the 1991–2020 average.

This tied 1999 and 2005 as the 23rd smallest Northern Hemisphere August snow extent on record. Snow extent for August has been at least nominally below average in each of the past six years.

The North America and Greenland snow cover extent for August was 2.48 million square kilometers (960,000 square miles), which was near the 1991–2020 average of 2.41 million square kilometers (930,000 square miles). This ranked as the 23rd largest August snow cover extent on record for North America, and was the largest August extent since 2018. As shown on the Rutgers University Global Snow Lab monthly departure map widespread areas of above average snow cover included the most northern areas of the Canadian Arctic Archipelago and areas of coastal Greenland. Below average snow cover extent included an area that stretched from southern Alaska southward along the Pacific Coast.

Snow cover extent over Eurasia in August was below average at 130,000 square kilometers (50,000 square miles), which was 140,000 square kilometers (50,000 square miles) below the 1991–2020 average. This tied 2007 and 2010 as the sixth-smallest August snow cover extent on record for Eurasia. It was the 22nd August in a row with Eurasian snow cover extent at least nominally below average.

August snow cover extent was below average along the full extent of the Himalayan mountain range. Above average snow cover extent was present on several islands of the Arctic Ocean including Svalbard, Franz Josef Land, and Severnaya Zemlya.

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 1979–2024 for a total of 46 years.

Globally, August 2024 sea ice extent was second lowest in the 46-year August record at 21.55 million square kilometers (8.32 million square miles). This was 11.2% below the 1991–2020 average, and slightly above last year's record low August extent of 21.07 million square kilometers (8.14 million square miles). August sea ice extent has been below average in each of the past ten years.

According to the National Snow & Ice Data Center Arctic sea ice retreat in August proceeded at a pace of 62,000 square kilometers (24,000 square miles) per day, similar to the 1981–2010 average pace for the month. As is typical for August, the loss slowed through the month in response to waning sunlight and decreasing air temperatures.

For the month as a whole, the average Arctic sea ice extent was the fourth smallest in the satellite record at 5.21 million square kilometers (2.01 million square miles). This was 1.22 million square kilometers (470,000 square miles) below the 1991–2020 average (approximately 19% below average). The average August Arctic sea ice extent has been below the 1991–2020 average in each of the past 18 years. August sea ice extent was below-average in all parts of the Arctic with the exception of the East Siberian Sea, which was near average and the Chukchi Sea which was above average.

The average Antarctic sea ice extent for August 2024 was the second smallest on record (16.34 million square kilometers or 6.31 million square miles), 1.5 million square kilometers (580,000 square miles) below the 1991–2020 average (approximately 8.4% below average). This year's August extent was approximately 840,000 square kilometers (330,000 square miles) greater than the lowest on record August Antarctic sea ice extent that occurred last year.