Southern California, better known for dry heat than tropical air, ranked among the most humid places in the United States on Thursday — even outpacing parts of muggy South Florida, weather experts said.
In Los Angeles, the dew point — a key measure of how oppressive humidity feels — climbed to nearly 70 degrees, according to weather analyst Colin McCarthy.
McCarthy summed up the rare conditions bluntly: “That is brutal humidity.”
Meteorologist Ben Noll said Los Angeles’ dew point may have risen even higher, reaching 73 degrees Thursday. Farther inland, the Salton Sea recorded an extraordinary dew point of 81 degrees.
Noll described Los Angeles’ humidity as “comparable to the Amazon rainforest” and said it may have been the city’s highest dew point ever recorded.
Forecasters linked the unusually sticky air to exceptionally warm Pacific waters, which have been fueling increased evaporation. A Category 3 severe marine heat wave was present near the Southern California coast.
There’s also a “heat dome,” Noll said, where an area of high pressure over the Southwest U.S. is making things more humid. Winds high in the atmosphere are pulling moist tropical air from Mexico into the Los Angeles area, Ryan Kittell, a meteorologist with the National Weather Service, told the New York Times.
According to McCarthy’s data, Thursday was one of the most humid days on record for Los Angeles. The last time it got nearly as humid were two days in September 2022.
The heat wave may be worsened by the El Niño weather pattern, weather experts said, with the coming days expected to record some hot temperatures.
An extreme heat warning from the National Weather Service remains in effect until 8 p.m. Friday, with temperatures potentially reaching up to 102 degrees.
“There is a high risk for dangerous heat illness, especially for sensitive groups like the very young, the very old, those without air conditioning and those active outdoors,” the warning said.
LA Mayor Karen Bass had announced that hundreds of facilities, including libraries and recreation centers, will be open for residents looking to survive the heat.
Some LA residents said they’re really feeling the effects of the humidity.
“I grew up in Virginia, which is way more humid than here, and I actually do think it has felt a little more humid this summer,” Lindsay Lazarus, 41, told the Times.
