Prevailing heat wave grips Southern California

A persistent heat wave continues across Southern California, with peak temperatures reaching triple digits in the valleys and some mountain regions, and little to no relief in sight through next weekend.

"Dangerously hot temperatures are expected across the interior through at least Monday as strong high pressure sits over the West Coast," the National Weather Service reported.

The hot, dry weather was creating wildfire danger across Southern California, with four brush fires burning in Riverside County and Los Angeles County officials keeping a close eye on the Angeles National Forest and other vulnerable sites.

Firefighters from Utah and Colorado have been called upon to help LA County officials with any potential brush fire response, the Angeles National Forest tweeted.

Forecasters said elevated fore weather conditions would exist through next weekend in the interior valleys, lower mountains and deserts, with brief critical fire weather conditions across the Antelope Valley and foothills.


Temperatures reached 109 degrees in Palmdale and Lancaster on Sunday, 102 in Santa Clarita, 100 in Northridge, 97 in Van Nuys, 91 in Pasadena and 87 in downtown Los Angeles.

Other areas to reach triple-digit heat include various parts of the Inland Empire.

Excessive heat warnings were in effect until at least 11 p.m. Monday in the San Gabriel Mountains and the Santa Clarita and Antelope Valleys. Less serious heat advisories were in effect for the same period in the San Gabriel and San Fernando valleys.

An excessive heat warning also exists in Riverside and San Bernardino counties through 8 p.m. Tuesday. 

Temperatures were only expected to drop a couple of degrees mid-week, but generally similar highs were forecast for the rest of the week, with next weekend's highs even possibly exceeding this weekend's numbers, according to the NWS.

Cooling centers were open across Los Angeles for those with no access to air conditioning. City emergency officials announced Sunday that hours at the centers were extended until 9 p.m. Monday.

RELATED: Where to cool off in LA during the extended heat wave

Most centers are served by one or more LA Department of Transportation Dash and Metro bus lines. Details are available at

"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 was 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.

As a result of the Riverside County fires, the South Coast Air Quality Management District issued a smoke advisory that was later extended through at least noon Monday.

AQMD officials urged people to limit exposure by remaining indoors with windows and doors closed, avoiding strenuous physical activity, using air conditions rather than swamp coolers or fans that bring in outside air, avoiding burning wood in fireplaces and fire pits, and wearing respirator masks while outdoors.

Meanwhile, many Southland beaches remain mired in morning low clouds and fog, with daytime temperatures in the upper 70s and 80s --- making those areas popular destinations this weekend.

FOX 11's Digital Team contributed to this report.