This year's winter was the warmest in the Northern hemisphere since temperature recording were first made, 125 years ago, an US governmental agency announced.
The combined natural temperature at ground level and on oceans' surface between December and February was three quarters higher than the normal average for these months, BBC News online reads.
Europe, Asia, West Africa, Brazil and the Northern half of the US had temperatures above the average, while Central USA and Saudi Arabia faced an unusual cold weather.
Experts say El Nino significantly contributed to the global warming.
The national Oceans and Atmosphere Administration expects temperatures rising one fifth of a degree every 10 years.