October 2016 tied with October 2003 as the third hottest on record across the globe, the U.S. National Oceanic and Atmospheric Administration announced Thursday. The agency attributed the cooling from a recent series of record monthly temperatures to the effect of the La Niña weather system.
NASA, though, this week called last month the second-hottest October in the 136 years in which records have been kept. It came in 0.18 degrees Celsius below October 2015, but 0.89 degrees warmer than the mean temperature for the month for 1951 to 1980.
Results from the two organizations usually differ a bit due to the use of different analysis methods, but the underlying data is essentially the same. For example, the two treat data from polar regions differently.
In any case, “We continue to stress that long-term trends are the important thing, much more so than monthly rankings,” Gavin Schmidt, director of NASA’s Goddard Institute for Space Studies, said in a press release.
The NOAA Numbers
The globally averaged temperature last month across land and ocean surfaces was 1.31 degrees Fahrenheit above the 20th century average for October of 57.1 degrees, according to a NOAA release. But it was 0.47 degrees below the record month of October 2015, which occurred during an upswing in the El Niño system.
The globally averaged land surface temperature in October landed at 1.37 degrees Fahrenheit above the 20th century average of 48.7 degrees. That makes it No. 16 in the temperature list from 1880 to 2016.
The globally averaged sea surface temperature, though, hit No. 2 for the record period, 1.3 degrees Fahrenheit above the 20th century monthly average but 0.25 degrees below peak heat in October 2015.
The Arctic sea ice extent last month was 28.5 percent below the 1981 to 2010 average at 980,000 square miles. “This was the smallest October extent since records began in 1979; the footprint of ‘missing’ ice was larger than the combined size of Alaska and Texas,” NOAA said. “Sea ice growth was abnormally slow during the first half of October. By month’s end, daily sea ice extent values were record low.”
Meanwhile, Antarctic sea ice extent was the second smallest on record for the month, trailing October 1986. It was 4 percent, or 290,000 square miles, below the 1981 to 2010 average.
The period from January to October 2016 holds the top spot for that 10-month stretch in the 1880-2016 record, coming in 0.18 degrees above former No. 1 2015, NOAA said.
Year to date, the average global temperature covering land and ocean surfaces was 1.75 degrees over the 20th century average. Both the globally averaged land and sea surface temperatures for the period beat the records set in 2015.
The NASA Numbers
The last three Octobers represent the top three temperature anomalies for the month, led by 2015 at 1.05 degrees Celsius above the October mean temperature for 1951 to 1980, the space agency said. The period since 2000 has produced the top 10 such anomalies.
NASA’s land-ocean temperature index shows the Arctic well above average temperatures, with warmth also seen in North Africa and the United States. A broad swath of cooler temperatures as found in Russia.