November 2015: Earth’s warmest November and 2nd warmest month of any kind on record

By Jeff Masters
17 December 2015 (Weather Underground) – November 2015 was Earth’s warmest November on record by a huge margin, according to data released by NOAA’s National Centers for Environmental Information (NCEI) on Thursday. November 2015 also had the second largest positive departure of temperature from average of any month among all 1631 months in the historical record that began in January 1880; only last month (October 2015) was more extreme. As shown in the table below, October and November 2015’s 0.97°C and 0.99°C departures from the 20th Century average beat the next eight runners-up by an unusually large margin, underscoring how unusual and extreme the current surge in global temperatures is. NASA also rated November 2015 as the warmest November in the historical record. November 2015’s warmth makes the year-to-date period (January – November) the warmest such period on record, according to both NOAA and NASA. November 2015 was the seventh consecutive month a monthly high temperature record has been set in NOAA’s database, and the ninth month of the eleven months so far in 2015. The potent El Niño event in the Eastern Pacific that crossed the threshold into the “strong” category in early July continued to intensify into mid-November, and is now slowly waning. Strong El Niño events release a large amount of heat to the atmosphere, typically boosting global temperatures by at least 0.1°C. This extra bump in temperature, when combined with the long-term warming of the planet due to human-caused emissions of heat-trapping gases like carbon dioxide, makes it virtually certain that 2015 will be Earth’s second consecutive warmest year on record. The lingering warmth from El Niño is likely to make 2016 a good bet to exceed even 2015’s warmth. NOAA’s top ten warmest global monthly departures from the 20th Century average:

0.99°C, Oct 2015
0.97°C, Nov 2015
0.91°C, Sep 2015
0.89°C, Mar 2015
0.88°C, Feb 2015
0.88°C, Jan 2007
0.87°C, Aug 2015
0.87°C, Jun 2015
0.86°C, Feb 1998
0.85°C, May 2015

Global satellite-measured temperatures in November 2015 for the lowest 8 km of the atmosphere were the warmest November readings in the 37-year record, according to the University of Alabama Huntsville (UAH). This is the second consecutive month the UAH database has registered a record monthly high. The lowest 8 km of the atmosphere heats up dramatically in response to moderate to strong El Niño events, with a time lag of about six months. [more]