WASHINGTON — The world's oceans this summer are the warmest on record.
The National Climatic Data Center, the government agency that keeps weather records, says the average global ocean temperature in July was 62.6 degrees. That's the hottest since record-keeping began in 1880. The previous record was set in 1998.
Meteorologists blame a combination of a natural El Nino weather pattern on top of worsening manmade global warming. The warmer water could add to the melting of sea ice and possibly strengthen some hurricanes.
The result has meant lots of swimming at beaches in Maine with pleasant 72-degree water. Ocean temperatures reached 88 degrees as far north as Ocean City, Md., this week.
The Gulf of Mexico, where warm water fuels hurricanes, has temperatures dancing around 90. Most of the water in the Northern Hemisphere has been considerably warmer than normal. The Mediterranean is about three degrees warmer than normal. Higher temperatures rule in the Pacific and Indian Oceans.
It's most noticeable near the Arctic, where water temperatures are as much as 10 degrees above average.
Breaking heat records in water is more ominous as a sign of global warming than breaking temperature marks on land. That's because water takes longer to heat up and doesn't cool off as easily, said climate scientist Andrew Weaver of the University of Victoria in British Columbia.
"This is another yet really important indicator of the change that's occurring," Weaver said.