Driven by exceptionally warm ocean waters, Earth smashed a record for heat in May and is likely to keep on breaking high temperature marks, experts have said.

May's average temperature on Earth of 15.54C was the warmest since records began in 1880, according to the United States National Oceanic and Atmospheric Administration.

Last month was especially hot in parts of Kazakhstan, Indonesia, Spain, South Korea and Australia, while the United States was not close to a record, just one degree warmer than the 20th century average. However, California is having a record hot first five months of the year, a full 5C above normal.

Kim Cobb, a climate scientist at Georgia Tech, said there was a good chance global heat records would keep falling, especially next year because an El Nino weather event was brewing on top of man-made global warming. An El Nino is a warming of the eastern tropical Pacific Ocean that alters climate worldwide and usually spikes global temperatures.


Ocean temperatures in May also set a record for the month. But an El Nino is not considered in effect till the warm water changes the air and that has not happened yet, according to the NOAA.

With the El Nino on top of higher temperatures from heat-trapping greenhouse gases, "we will see temperature records fall all over the world", wrote Pennsylvania State University climate scientist Michael Mann in an email.