Surface water temperatures in August hit the highest they have ever been in at least a century, according to researchers with the Scripps Institution of Oceanography at UC San Diego.
On Wednesday, August 1, water samples pulled from the end of Scripps Pier showed a reading of 78.6 degrees Fahrenheit. Researchers said it broke an all-time record.
Since 1916, scientists have been tracking water temperatures near the pier in La Jolla every single day. It's one of the longest ongoing data sets in history.
But why are the waters warm now? Researchers are not exactly sure but have theories.
"Since 2014, we’ve had a lot of warming in the Pacific," said Melissa Carter, a programmer analyst with the Scripps Institution of Oceanography. "We also have a lot of water coming up from the south, which is warmer."
Beachgoers in La Jolla noticed the warmth of the ocean on Thursday.
"It's like bathwater out there right now," said Kyle Graham.
While scientists said it is the best time for humans to go swimming in a century, they are concerned the higher ocean temperatures might affect the ecosystem.
"We did see that phytoplankton were decreasing over a large scale," said Carter.
Warmer waters can also affect the development of plankton and kelp, which are eaten by certain fish. Fish found near coastal waters must then search offshore for food.
Seaborne diseases are more common and spread more quickly in warmer waters too.
Heal the Bay coastal marine scientist Mary Luna told NBC that scientists will likely see major changes in sea life if the warming trend continues.
"Off the coast of California it is believed that sustained warmer water temperatures will result in shifts, expansions or reductions in the range of commercially important species or the species that depend on them," she said.
Scientists said there is no way to predict how long the warm water will last, so enjoy it while you can.