Near-record number of Category 5 storms driven by record-warm ocean heat and El Niño
There were nine Category 5 storms in 2015, which is the second-highest total on record. Record-warm ocean temperatures fed the unusually high number of strong storms, with especially warm readings across tropical and subtropical areas. El Niño played a large role by spreading warm water across vast swaths of the Pacific. However, Earth has also experienced a decade of intensified heat storage in the deep ocean (which scientists say is largely responsible for the temporary slowdown in the rate of surface warming from 2000 to 2012).