Los Angeles is experiencing an unusually humid summer, with mugginess more typical of the Deep South than Southern California, according to meteorologists. The increased humidity results from atmospheric circulation changes linked to the North American monsoon, a seasonal pattern that brings moisture from the Pacific Ocean and the Gulf of California into the southwestern United States.

Bryan Lewis, a meteorologist with the National Weather Service in Oxnard, explained that while the monsoon has been active over the region for an extended period, it has not produced the rainstorms that typically provide some relief from summer heat. Additionally, the area has been influenced by the remnants of Tropical Storm Elida followed by moisture carried in from Hurricane Fausto, both of which have contributed to the sticky conditions.

Contributing further to the discomfort is the notably warm ocean water off the Southern California coast. Measurements on Sunday showed sea surface temperatures of 74 degrees Fahrenheit near Hermosa Beach and 70 degrees off Zuma Beach. At Scripps Pier in La Jolla, temperatures reached 75.7 degrees Monday afternoon, considerably higher than the typical 68 degrees expected at this time of year.

Daniel Cayan, a climate researcher at Scripps Institution of Oceanography at the University of California San Diego, attributed the elevated ocean temperatures to a persistent weather pattern established over the last three months. The pattern has allowed abundant sunshine to heat surface waters while calm winds have prevented cooler water from mixing upward. This has created a “warm lens” of water along the Southern California coastline that extends further south.

Officials say this combination of atmospheric moisture and warm coastal waters is making the summer heat feel more oppressive than usual, posing challenges for residents accustomed to the region’s typically dry, breezy conditions.