Temperatures measured by government meteorological offices using land, sea and satellite data suggest this year’s global high was very close to those of 2011, 2008, 2006 and 2003. Overall, temperatures were 0.70C above the 1951-1990 baseline temperature average.
But Nasa warned against reading too much into a single month’s records. “The key issue for climate are the long-term trends, not individual months”, said Nasa-GISS director Gavin Schmidt.
Earlier this year it looked certain that an El Niño event would develop in the Pacific ocean following a rise in sea temperatures, which could be expected to result in extreme weather effects around the world by Christmas. However, expectations of a strong El Niño have since faded.
The US west continues to swelter under a prolonged drought while much of the north and eastern US has been noticeably cooler than average for much of 2014. Record temperatures up to 4C above normal have been recorded in west Antarctica, even as the extent of sea ice has reached record levels.