Three separate climate data sets from NASA, the Japan Meteorological Agency and the National Oceanic and Atmospheric Administration (NOAA) recorded that last month was the warmest month on record.

A report released by the National Oceanic and Atmospheric Administration (NOAA) yesterday records last month as the warmest May for the Earth ever recorded.

The cause of the heat, according to NOAA, was the unusual warmth in the oceans, which make up more than 70% of the Earth’s surface. The combined average temperature over the entire planet in May 2014 was 59.93 degrees Fahrenheit, 1.33 above the 20th-century average.

Last month was also the 351st consecutive month with a global temperature above the 20th-century average.

The spring of 2014 – defined as the months of March, April and May – was the second-warmest spring ever recorded. The year to date is the fifth warmest on record, so far, the climate center reported.

El Niño, a warming of tropical Pacific Ocean water that affects climate and weather patterns around the world, was not present yet in May, however the Climate Prediction Center estimates that there is about a 70% chance that El Niño conditions will develop during the summer of 2014 and an 80% chance it will develop during the fall and winter.

The two warmest years on record, 1998 and 2010, occurred during El Niños.

Global temperature records go back to 1880.