Why does LA feel so humid right now? - LA Public Press

What the report says

LA Public Press reports that Los Angeles’ usual summer “dry heat” has recently given way to noticeably muggy conditions, with heavier air, warmer nights and moderate temperatures feeling more oppressive across Southern California. Meteorologists cited by the outlet point to a mix of persistent high pressure over the South-Central U.S., warmer-than-normal coastal ocean water and tropical moisture moving north from storms off Mexico.

Lisa Phillips, a National Weather Service meteorologist, told LA Public Press that Southern California has been sitting on the west side of a high-pressure system, drawing warmer, more humid air into the region. She also said unusually warm Pacific waters have weakened the cooling effect of the marine layer, meaning the coast’s natural “air conditioning” has not formed as reliably. Daniel Swain, a climate scientist with the University of California Agriculture and Natural Resources, said nearshore ocean temperatures are a major reason LA County has felt warmer and more humid.

The report explains that dew point, not the humidity percentage in weather apps, better reflects how sticky the air feels. Swain said coastal Southern California typically sees summer dew points near 60 degrees, but recent readings have often reached 65 to 70 degrees, levels many people find uncomfortable. He said the stretch is among the most humid mid-July periods in decades, based on available datasets.

While daytime temperatures have been above normal, Phillips said they have not been record-breaking, with Downtown LA staying below daily records cited for July 15 and 16. The concern, the report notes, is that humid heat and warm nights can reduce the body’s ability to cool down, posing added strain for people without reliable air conditioning, older adults, children and those with health conditions.