Every month University of Alabama in Huntsville climatologists John Christy and Roy Spencer publish the latest global temperature trend data obtained from NOAA satellites. For the month of September 2015 they report:
Global Temperature Report: September 2015
In the tropics, warmest September in the satellite temperature record
Global climate trend since Nov. 16, 1978: +0.11 C per decade
September temperatures (preliminary)
Global composite temp.: +0.25 C (about 0.45 degrees Fahrenheit) above 30-year average for September.
Northern Hemisphere: +0.34 C (about 0.61 degrees Fahrenheit) above 30-year average for September.
Southern Hemisphere: +0.17 C (about 0.31 degrees Fahrenheit) above 30-year average for September.
Tropics: +0.55 C (about 0.99 degrees Fahrenheit) above 30-year average for September.
Notes on data released:
An El Niño Pacific Ocean warming event continues to heat the tropics, although there is significant heat that has yet to be transferred from the ocean into the atmosphere, said Dr. John Christy, director of the Earth System Science Center at The University of Alabama in Huntsville. Temperatures in the tropics averaged 0.55 C (about 0.99° F) warmer than seasonal norms in September, a new record for tropical Septembers surpassing the previous record of +0.52 C set in September 2009.
Globally it was the fifth warmest September in the satellite record. It was also the fourth warmest September in the Northern Hemisphere.
While it is too early in the year to make any meaningful forecast or prediction about where 2015 will finish in the rankings of warm and cold years, it is reasonable to expect the heat from the El Niño to continue to spread across more of the globe during the next three months. Through the first nine months of the year, comparing January through September throughout the satellite temperature record starting in 1979, the first nine months of 2015 ranked fourth overall, with an average global temperature that was 0.22 C warmer than seasonal norms. The first nine months of 1998 were warmest at 0.56 C, followed by 2010 at 0.41 C and 2002 at 0.24 C warmer than seasonal norms.