World Meteorological Organization Secretary-General Michel Jarraud told the BBC it was likely that La Nina would reduce temperatures by a fraction of a degree.

The effects of La Nina and El Nino in the Pacific resonate round the world. While El Nino warms the planet, La Nina cools it. This year, the Pacific is in the grip of a powerful La Nina current that has contributed to heavy rain in Australia and record low temperatures in parts of China, the BBC said Friday.

Jarraud, however, said temperatures this year will still be well above the average.

"When you look at climate change you should not look at any particular year," he said. "You should look at trends over a pretty long period and the trend of temperature globally is still very much indicative of warming."