Temperatures could hit a record 113 in Palmdale on Friday, which would break the record set in 2007 and 1961. In Lancaster, temperatures are expected to reach 115, which falls a few degrees short of the record set in 2013.
More high temperatures and dangerously hot conditions are expected Friday in other parts of Southern California and will last through the weekend.
Forecasters noted that the beach will be the place to be this weekend, noting that coastal areas could remain cool "even during the peak of the heat wave this weekend."
Elsewhere, however, the heat will be on starting Thursday and persisting until at least Monday.
"The heat is expected to build each day, especially in the Antelope Valley, lower mountain elevations and the interior valleys such as the Santa Clarita, Salinas and Cuyama Valley," according to the NWS. "Dangerous heat will is expected to develop in many of these areas Thursday, then intensify to Excessive Heat Warning levels by Friday."
In the Santa Clarita Valley, the 5 and 14 Freeway corridors and the San Gabriel Mountains, an excessive heat warning took effect at 10 a.m. Friday and will remain in place until 10 a.m. Monday.
Forecasters said that area could see temperatures of up to 104 degrees, with temperatures at night dipping only into the upper 60s to low 80s. After 10 a.m. Monday, a less serious excessive heat watch will be in effect throughout the day in those areas.
In the Antelope Valley and accompanying foothills, an excessive heat warning will also be in effect through 10 a.m. Monday, will temperatures possibly peaking at 114 degrees, with overnight lows dropping only into the 70s and 80s, according to the NWS.
The San Fernando and San Gabriel valleys and the Santa Monica Mountains Recreational Area will be under a less severe heat advisory until 11 p.m. Sunday, with temperatures up to 102 degrees possible, forecasters said.
In Orange County, an excessive heat warning will be in effect until 8 p.m. Tuesday, with temperatures expected as high as 104 degrees.
"Extreme heat will significantly increase the potential for heat-related illnesses, particularly for those working or participating in outdoor activities," NWS forecasters warned. "Drink plenty of fluids, stay in an air-conditioned room, stay out of the sun, and check up on relatives and neighbors. Young children and pets should never be left unattended in vehicles under any circumstances."
The high heat is expected to contribute to "elevated to brief critical fire conditions" in desert, mountain and interior valley areas. Those areas will see humidity levels in the 5% to 15% range. Winds are expected to be relatively light, but some higher gusts are possible in traditionally wind-prone areas.
Elevated temperatures are likely to continue into next week, although more onshore flow is expected, helping to cool things off in the valleys. But mountains and interior areas "will likely continue to sizzle," forecasters said.
The metropolitan Los Angeles area is not facing any heat advisories or warnings, but it will still be warm. Forecasters said the L.A. area in general will see temperatures around 90 during much of the heat wave, with coastal areas the place to be -- thanks to highs of about 80.