The temperature of the oceans' surface rose to 20.96 degrees Celsius (69.7 degrees Fahrenheit) on July 30, according to European Union climate observatory data.
The previous record was 20.95 C in March 2016.
According to scientists the average sea surface temperature record was reached on April 4 this year at 21.06 C, overtaking the previous high of 21.01 C in March 2016. On August 1, average temperatures were 21.03 C, pointing out that oceans have absorbed 90% of the excess heat produced by human activity since the dawn of the industrial age.
"The ocean heat wave is an immediate threat to some marine life," said Piers Forster of the International Center for Climate at Britain's University of Leeds.
"We are already seeing coral bleaching in Florida as a direct result, and I expect more impacts will surface," Forster said.
Source: Qatar News Agency