2013 is on course to be among the top ten warmest globally since modern records began 163 years ago.
Data from the World Meteorological Organization found that global land and ocean temperatures between January and September to be 0.48°C above the average between 1961 and 1990.
That makes the period the joint seventh warmest on record, tied with 2003.
The WMO's provisional annual statement was released to inform negotiators at the United Nations climate change conference, which is taking place in Warsaw in Poland.
The data shows January to September 2013 was warmer than the same period in both 2011 and last year, when La Niña had a cooling influence.
Temperatures so far this year are around the average for 2001 to 2010 - the warmest decade on record.
The provisional WMO statement also shows that Arctic Sea ice recovered slightly after an unprecedented level of melt in 2012.
However, the WMO says 2013 still saw one of the lowest levels on record.
The statement also confirms that global sea level reached a new record high.
Making reference to the devastation wreaked on the Philippines by Typhoon Haiyan, WMO Secretary General Michel Jarraud said while individual tropical cyclones cannot be directly attributed to climate change, higher sea levels are already making coastal populations more vulnerable to storm surges.