The heat wave hitting Southern California isn't going away.
The National Weather Service says the Southland will continue to swelter well into next week, bringing triple digit temperatures to inland valleys along with elevated fire danger and the potential for power outages.
An excessive-heat warning will be in effect through Friday night, but the heat wave is likely to persist until the following Thursday, according to the weather service.
Palmdale, Lancaster and Woodland Hills are facing the brunt of the heat: All three locations are forecast to stay in the triple digits through Labor Day.
Woodland Hills reached 112 degrees Tuesday, tying a record for the date set in 1996. Temperatures broke records in Lancaster and Sandberg, where highs reached 109 and 103, respectively.
Lancaster's previous record for the date was in 1998, when the temperature reached 107. In Sandberg, an earlier record of 97 degrees was set in 2007.
The heat is putting strain on the state's electricity grid.
The California Independent System Operator issued a "flex alert" Tuesday morning, calling for voluntary electricity conservation from 2 p.m. to 9 p.m. Tuesday.
"Persistent hot temperatures and tight supply can strain the power grid, as air conditioner use increases," the grid operator said in a statement. "The forecast peak use today, Aug. 29, is expected to exceed 48,000 megawatts, which if met will be the highest demand on the grid seen so far this year."
In Northridge on Tuesday night, roughly 10,500 customers were without power, according to Michael Ventre, a spokesman with the Los Angeles Department of Water and Power. Other outages were scattered across the agency's service area.
In Boyle Heights earlier in the evening, 3,300 customers were temporarily without power. By 7:30 p.m., power was restored.
"Typically that's what happens in temperatures like this," Ventre said.
Daily records were also broken Monday when temperatures reached 111 in Woodland Hills, 109 in Lancaster, 108 in Palmdale and 104 in Sandberg, according to the weather service. Records in the latter three areas were last set in 2008, when temperatures reached 107 in Lancaster and Palmdale and 97 in Sandberg.
Temperatures got so high that traffic lights stopped working in Santa Clarita on Monday.
Air quality will suffer in a large stretch of the Southland as the heat wave continues.
The South Coast Air Quality Management District said readings of ground-level ozone are likely to reach unhealthy levels in the Santa Clarita Valley, the San Gabriel Mountains, portions of the San Fernando and San Gabriel valleys, the Inland Empire and the San Bernardino Mountains.
Jeffrey Gunzenhauser, Los Angeles County's interim health officer, advised people in Pomona, the San Gabriel Valley and Santa Clarita Valley with heart disease, asthma or other respiratory diseases to minimize outdoor activities.
Times staff writer Alene Tchekmedyian contributed to this report.
10:15 p.m.: This article was updated with information about another power outage.
8:05 p.m.: This article was updated with information about record-breaking heat and a power outage in Boyle Heights.