Monthly Report Summary Information

Global Summary Information - September 2016

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Note: With this report and data release, the National Centers for Environmental Information is transitioning to improved versions of its global land (GHCN-M version 3.3.0) and ocean (ERSST version 4.0.0) datasets. Please note that anomalies and ranks reflect the historical record according to these updated versions. Historical months and years may differ from what was reported in previous reports. For more, please visit the associated FAQ and supplemental information.

Monthly record warm streak ends; September second warmest on record for the globe

Year-to-date continues to be record warm

Selected Climate Events & Anomalies for September 2016

September 2016 Blended Land and Sea Surface
Temperature Percentiles

Global highlights: September 2016

• The September temperature across global land and ocean surfaces was 1.60°F above the 20th century average of 59.0°F. This was the second highest for September in the 1880–2016 record, 0.07°F cooler than the record warmth of 2015 when El Niño conditions were strengthening.
• The September globally averaged land surface temperature was 2.32°F above the 20th century average of 53.6°F. This value was the highest September land global temperature in the 1880–2016 record, exceeding the previous record set in 2015 by 0.20°F. In the 137-year record. The 12 highest September global land temperatures have all occurred during the 21st century.
• The September globally averaged sea surface temperature was 1.33°F above the 20th century monthly average of 61.1°F, tying with 2014 as the second highest global ocean temperature for September in the 1880–2016 record, behind 2015 by 0.16°F.
• The September temperature for the lower troposphere (roughly the lowest 5 miles of the atmosphere) was the highest in the 1979–2016 record, at 1.03°F above the 1981–2010 average, as analyzed by the University of Alabama in Huntsville* (UAH) using UAH version 5.6. It was also the highest on record, at 0.83°F above the 1981–2010 average, as analyzed by Remote Sensing Systems* (RSS).
• The September temperature for the mid-troposphere (roughly 2 miles to 6 miles above the surface) was the highest for September in the 1979–2016 record, at 0.90°F above the 1981–2010 average, as analyzed by UAH. It was also the highest on record, at 0.76°F above the 1981–2010 average, as analyzed by RSS. After removing the influence of temperatures above 6 miles in altitude, the University of Washington, using data analyzed by the UAH and RSS, calculated temperature departures from the 1981–2010 average to be 1.13°F (highest) and 0.94°F (highest), respectively.
• On September 10, Arctic sea ice reached its annual minimum extent at 1.60 million square miles, statistically tying 2007 as the second smallest extent in the 1979–2016 satellite record, according to the National Snow and Ice Data Center. This was 800,000 square miles below the 1981–2010 average and five days earlier than average. The 2016 Arctic sea ice minimum was 290,000 square miles larger than the record small minimum that occurred in 2012.
• The average Arctic sea ice extent for September 2016 was 710,000 square miles (27.8 percent) below the 1981–2010 average. This was the fifth smallest September extent since records began in 1979, according to analysis by the National Snow and Ice Data Center using data from NOAA and NASA. Below-average sea ice was observed across most regions of the Arctic, with much below-average sea ice across the Beaufort, Chukchi and East Siberian Seas. Rapid ice growth during the second half of September allowed the monthly average sea ice extent to somewhat rebound from the second lowest daily extent observed on September 10.
• Antarctic sea ice extent during September 2016 was 150,000 square miles (2.0 percent) below the 1981–2010 average. This was the fifth smallest Antarctic sea ice extent on record for September and the smallest since 2002. On August 31, the Antarctic sea ice reached its annual maximum extent at 7.12 million square miles. This was the 10th smallest maximum sea ice extent on record for the Antarctic and the earliest occurrence of the maximum extent in the 1979-2016 satellite record.

Global highlights: Year-to-date (January–September 2016)

• The year-to-date temperature across global land and ocean surfaces was 1.78°F above the 20th century average of 57.5°F. This was the highest for January-September in the 1880–2016 record, surpassing the previous record set in 2015 by 0.23°F.
• The year-to-date globally averaged land surface temperature was 2.84°F above the 20th century average. This was the highest for January-September in the 1880–2016 record, exceeding the previous record of 2015 by 0.53°F.
• The year-to-date globally averaged sea surface temperature was 1.40°F above the 20th century average. This was the highest for January-September in the 1880–2016, surpassing the previous record of 2015 by 0.14°F.
• The January–September temperature for the lower troposphere was the highest in the 1979–2016 record, at 1.12°F above the 1981–2010 average, as analyzed by the University of Alabama in Huntsville* (UAH) using version 5.6. It was also highest on record, at 0.99°F above the 1981–2010 average, as analyzed by Remote Sensing Systems* (RSS).
• The January–September temperature for the mid-troposphere tied with 1998 as the highest for January–September in the 1979–2016 record, at 0.92°F above the 1981–2010 average, as analyzed by UAH. It was second highest on record, at 0.88°F above the 1981–2010 average, as analyzed by RSS. After removing the influence of temperatures above 6 miles in altitude, the University of Washington, using data analyzed by the UAH and RSS, calculated temperature departures from the 1981–2010 average to be 1.13°F (highest) and 1.08°F (highest), respectively.

* Please note: the UAH and RSS referenced in this report are versions that have completed a research-to-operations (R2O) transition involving scientific, technical and administrative processes designed to ensure operational reliability. Both groups have new versions of their products at some stage of the R2O process and will be incorporated in this report when the R2O process is complete.

For extended analysis of global temperature and precipitation patterns, please see our full September report.