From NCDC: Global Highlights
- The average combined global land and ocean surface temperature for September 2012 tied with 2005 as the warmest September on record, at 0.67°C (1.21°F) above the 20th century average of 15.0°C (59.0°F). Records began in 1880 (133 years of data).
- The globally-averaged land surface temperature for September 2012 was the third warmest September on record, at 1.02°C (1.84°F) above average. The globally-averaged ocean surface temperature tied with 1997 as the second warmest September on record, at 0.54°C (0.97°F) above average.
The average global temperature across land and ocean surfaces during September was 0.67°C (1.21°F) above the long-term 20th century average. This temperature ties with 2005 as the record warmest September in the 133-year period of record. The Northern Hemisphere tied with 2009 as second warmest on record, behind 2005. The Southern Hemisphere also ranked second warmest on record, behind 1997. It was also the highest departure from average for any month in the Southern Hemisphere since May 2010. It also marked the 36th consecutive September and 331st consecutive month with a global temperature above the 20th century average. The last below average September temperature was September 1976, and the last below average temperature for any month was February 1985.