The globally averaged temperature for August 2017 over both land and ocean surfaces was 61.59°F (16.44°C), or 1.49°F (0.83°C) above the 20th century average of 60.1°F (15.6°C). This was the third highest for the month of August in the 138-year global temperature dataset record of the National Oceanographic and Atmospheric Administration (NOAA). The NOAA monthly temperature records form a continuous data set from 1880–2017. The highest August temperature on record was in 2016, and 2015 was the second highest. August 2017 also marks the 41st consecutive August and the 392nd consecutive month with temperatures at least nominally above the 20th century average. The three month globally averaged temperature across land and ocean surfaces combined for June–August 2017 was the third highest for this period on record since recording began, behind 2016 (highest) and 2015 (second highest).
For land surface only, the globally averaged temperature was 59.01°F (15.01°C), or 2.11°F (1.17°C) above the 20th century average of 56.9°F (13.8°C). This was the second highest August land global temperature on record, after the record year 2016.
Sea surface temperature globally averaged in August was 62.68°F (17.04°C). This was 1.28°F above the 20th century monthly average of 61.4°F (16.3°C) and was the fourth highest global ocean temperature for August on record. The extent of Arctic sea ice coverage in August 2017 was 683,000 square miles (1,768,962 sq km) which was 24.3 percent below the 1981–2010 average and this was the third smallest August sea ice extent since records began in 1979. The Antarctic sea ice extent for August was 250,000 square miles (647,497 sq km) which was 3.6 percent below the 1981–2010 average. This was the second smallest extent for Antarctic sea ice since records began in 1979, behind 2002.
This information on global temperature is included in a monthly summary, developed by scientists at NOAA’s National Centers for Environmental Information. Sea ice analysis and records are by the National Snow and Ice Data Center and are based on data from NOAA and NASA.