The globe had a top-six warm August and June-August period; the Northern Hemisphere had near-record warm summer
The global temperature for August 2021 was the sixth highest for the month of August in the 142-year NOAA record, which dates back to 1880. The year-to-date (January-August) global surface temperature was also the sixth highest on record. According to NCEI’s Global Annual Temperature Rankings Outlook, it is very likely (> 99.0%) that the year 2021 will rank among the 10 warmest years on record, but with less than a 2% chance for it to rank among the five warmest years on record.
This monthly summary, developed by scientists at NOAA’s National Centers for Environmental Information, is part of the suite of climate services NOAA provides to government, business, academia and the public to support informed decision-making.
Monthly Global Temperature
The August 2021 global surface temperature was 1.62°F (0.90°C) above the 20th-century average of 60.1°F (15.6°C) -- the sixth-warmest August in the 142-year record. Nine of the 10 warmest Augusts have occurred since 2009. August 2021 also marked the 45th consecutive August and the 440th consecutive month with temperatures, at least nominally, above the 20th-century average.
The August global land-only surface temperature was the second highest for the month. Only August of 2016 was warmer. The near-record warm global land surface temperature was mainly driven by the record-warm Northern Hemisphere land surface August temperature.
Regionally, Asia had its second-warmest August on record, behind August 2016. Africa had its third-warmest August. North America, South America and Oceania had a top-nine warm August on record. Although Europe had an above-average August temperature, it was the coolest August since 2008.
Temperatures were much above average across parts of eastern North America, South America, Africa, western, northern and southern Asia, as well as parts of the Atlantic Ocean, northern Indian Ocean and northern and western parts of the Pacific Ocean. Temperatures were cooler than average across parts of the central and southern Pacific Ocean and across central-eastern Asia.
Sea Ice
August 2021 Arctic (left) and Antarctic (right) sea ice extent. (Courtesy of NOAA NCEI.)
The August 2021 Arctic sea ice extent averaged 2.22 million square miles, which is 560,000 square miles below the 1981-2010 average and the 10th-smallest August extent in the 43-year record, according to an analysis by the National Snow and Ice Data Center (NSIDC) using data from NOAA and NASA.
The Antarctic sea ice extent for August 2021 was 7.0 million square miles or 160,000 square miles above average and the fifth highest for August on record. This was also the largest August sea ice extent since 2014.
Seasonal Global Temperature
The June-August 2021 global surface temperature was also 1.62°F (0.90°C) above the 20th-century average of 60.1°F (15.6°C) and the fourth-warmest June-August period in the 142-year record. Nine of the 10 warmest June-August periods have occurred since 2010.
The June-August period is defined as the Northern Hemisphere’s meteorological summer and the Southern Hemisphere’s meteorological winter. The Northern Hemisphere summer 2021 temperature departure tied with 2019 as the second-warmest summer on record. Summer of 2020 was warmer by only 0.07°F (0.04°C). The Northern Hemisphere’s land surface temperature departure was the highest on record, contributing to the highest global land surface June-August temperature. Meanwhile, the Southern Hemisphere had its fifth-warmest winter (tied with 1998) on record.
Regionally, Asia had its warmest June-August on record. North America and Africa had their second- and third-warmest June-August on record, respectively. South America, Europe and Oceania had a top-nine warm June-August period on record.
During the three-month period, temperatures were much above average across parts of North America, South America, Europe, Africa and Asia as well as parts of the western Pacific Ocean, the Atlantic and Indian Oceans. In contrast, parts of the North Atlantic, the central and eastern Pacific Ocean and India had near- to cooler-than-average June-August temperatures.
Global Tropical Cyclones
The Atlantic basin had above-average hurricane activity during August 2021 with six named storms, including three hurricanes, two of which became major hurricanes (Grace and Ida). The eastern North Pacific basin had near-normal activity with five named storms during the month, two of which became hurricanes including one major hurricane (Linda). The West Pacific basin had its lowest Accumulated Cyclone Energy (ACE; measures the strength and duration of tropical storms and hurricanes) since 1981 with only four named storms and no typhoons during the month. Overall, the global tropical cyclone activity from January-August 2021 was below average, in part due to the lack of activity across the West Pacific Ocean.
For a more complete summary of climate conditions and events, see our August 2021 Global Climate Report.
