A heat advisory was in effect Wednesday for Los Angeles County valleys and the San Gabriel Mountains as temperatures pushed upward, with Wednesday expected to be the hottest day of the week before a cool-down arrives for the weekend.
The advisory, issued by the National Weather Service, will be in effect through 9 p.m. Thursday for the valleys and San Gabriel Mountains, where forecasters said temperatures could push in to the low to mid 90s.
The advisory was originally expected to remain in place for the same duration for Los Angeles County inland coastal areas, including downtown Los Angeles, but that advisory will now expire at 9 p.m. Wednesday, according to the NWS. Forecasters said the coastal areas will experience “unseasonably hot conditions,” with temperatures in the mid- to upper-80s downtown.
Forecasters said the heat is expected to peak Wednesday, lingering into Thursday, as a strong area of high pressure expands into Southern California.
“Admittedly under normal conditions, these temperatures would not necessitate any heat products,” NWS forecasters said regarding the heat advisory. “However, given the current influx of visitors and numerous outdoor events across the county, there is a higher risk for heat-related problems, especially given that humidities will be higher than normal.”
Conditions are expected to change quickly after Thursday, with a strong onshore flow anticipated by Friday morning that will lead to low clouds across coastal and valley areas — with beaches likely not seeing any clearing.
As a result, temperatures will fall, likely to “a few degrees below normal” in many areas. By Saturday, “June Gloom will be back with a vengeance” through at least Tuesday, according to the NWS.
“Max temps will mostly be in the 70s across the coasts/valleys (mid to upper 60s at the beaches) and only lower to mid 80s for the inland areas,” according to the NWS. “These max temps are 3 to 5 degrees cooler than normal at the coasts and 5 to 10, locally 12, below normal across the valleys and inland areas.”