Summary Information

The State of the Climate Summary Information is a synopsis of the collection of national and global summaries released each month.


Global Summary Information - September 2015

See Full Report

Note: This month's global analysis contains slightly less data than is typical, especially in parts of western Africa and western South America. This does not affect the rankings and is taken into account in the uncertainty information in the full report.


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.


Global average temperature record high for September and January–September;

Separately, global oceans and global land were both highest on record for these periods of time


Global highlights: September 2015

  • The September average temperature across global land and ocean surfaces was 1.62°F (0.90°C) above the 20th century average&mdash. This was the highest September temperature on record, surpassing the previous record set last year by +0.12°F (+0.19°C). September's high temperature was also the greatest rise above average for any month in the 136-year historical record, surpassing the previous record set in both February and March this year by 0.02°F (0.01°C).
  • The September globally-averaged land surface temperature was 2.09°F (1.16°C) above the 20th century average. This was also the highest for September in the 1880–2015 record, surpassing the previous record set in 2009 by +0.16°F (+0.09°C). Record warmth was observed across much of South America and parts of Africa, the Middle East, Europe, and Asia.
  • The September globally-averaged sea surface temperature was 1.46°F (0.81°C) above the 20th century average. This was the highest temperature for September in the 1880–2015 record, surpassing the previous record set in 2014 by +0.13°F (+0.07°C).
  • On September 11th, Arctic sea ice reached its annual minimum extent at 1.70 million square miles, the fourth smallest extent in the 1979–2015 satellite record, according to the National Snow and Ice Data Center. This was 699,000 square miles below the 1981–2010 average, but 394,000 square miles larger than the record small minimum that occurred in 2012.
  • The average Arctic sea ice extent for September 2015 was 720,000 square miles (28.88 percent) below the 1981–2010 average. This was the fourth 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, while near-average sea ice was observed in the Barents Sea.
  • Antarctic sea ice extent during September 2015 was 100,000 square miles (0.53 percent) below the 1981–2010 average. This was the 16th smallest Antarctic sea ice extent on record and smallest since 2008. The maximum Antarctic sea extent was not reached until the month of October, and will be reported next month.

Global highlights: Year-to-date (January–September 2015)

  • The year-to-date temperature across global land and ocean surfaces was 1.53°F (0.85°C) above the 20th century average. This was the highest for January–September in the 1880–2015 record, surpassing the previous record set in 2014 by 0.19°F (0.12°C).
  • The year-to-date globally-averaged land surface temperature was also the highest for January–September in the 1880–2015 record at 2.32°F (1.29°C) above the 20th century average. This value surpassed the previous record of 2007 by 0.31°F (0.17°C).
  • The year-to-date globally-averaged sea surface temperature was 1.24°F (0.69°C) above the 20th century average and the highest for January–September in the 1880–2015 record. This value surpassed the previous record of 2010 by +0.11°F (+0.06°C).
  • For extended analysis of global temperature and precipitation patterns, please see our full September report