Average global temperatures in 2015 are likely to be the hottest ever recorded, according to the World Meteorological Organization.
The effects of climate change have led to global temperature increases of 1 degree Celsius above the pre-industrial era, according to the WMO.
"2015 is likely to be the hottest year on record, with ocean surface temperatures at the highest level since measurements began. It is probable that the 1 degree Celsius threshold will be crossed," said WMO Secretary-General Michel Jarraud. "This is all bad news for the planet."
The WMO says this is due to a combination of global warming and the El Niño oceanic phenomenon.
According to the WMO report, the five-year period from 2011-2015 has been the warmest on record "with many extreme weather events - especially heatwaves - influenced by climate change."
It says South America is having its hottest year on record, as is Asia, while Africa and Europe are having their second hottest.
"Greenhouse gas emissions, which are causing climate change, can be controlled," Jarraud said. "We have the knowledge and the tools to act."
The report comes just a week before world leaders meet in Paris for the 2015 United Nations Climate Change Conference.