Hot and dry conditions were expected through the Labor Day holiday, with parts of the Southland under heat advisories Sunday and Monday and critical fire conditions through Tuesday.
Highs will break 100 degrees Sunday in the mountains and the San Fernando, Santa Clarita and Antelope valleys, according to the National Weather Service.
In inland Orange County — where highs of 97 to 102 degrees were expected — a heat advisory was in effect until 8 p.m. Sunday.
Sunday was forecast to be the warmest day for the valleys, while Monday will be the warmest for the mountains and the far-inland areas, the NWS said.
Downtown Los Angeles was expected to see a high of around 90 degrees on Sunday and 89 on Monday. Pasadena’s high of 99 Sunday was expected to drop to 93 on Monday.
In the San Fernando Valley, Woodland Hills will heat up to 104 on Sunday, then drop to 99 on Labor Day.
Santa Clarita will see highs of 103 on Sunday before dropping to 97 on Monday.
In the Antelope Valley, it will be 103 on Sunday in Lancaster, then 104 on Monday, according to the NWS.
The Los Angeles County Health Officer issued a heat alert for the West San Fernando Valley on Sunday and Monday, and a heat advisory Monday for the Santa Clarita and Antelope valleys.
“High temperatures are not just an inconvenience, they can be dangerous and even deadly. But we can protect ourselves, our families, and our neighbors if we take steps to remain cool and hydrated,” Dr. Muntu Davis said. “It is critically important to never leave children, elderly people, or pets unattended in homes with no air conditioning and particularly in vehicles, even if the windows are `cracked’ or open, as temperatures inside can quickly rise to life-threatening levels.
“If you have an elderly or infirm neighbor who is without air conditioning, check on them throughout the day.”
Skies will be mostly clear with only minimal morning low clouds through the long weekend.
Meteorologists said a ridge of high pressure building over Central California will dominate the region, reducing relative humidity and creating bone-dry conditions.
The high temperatures, combined with the extremely low humidity, will create critical fire weather conditions through Tuesday over the valleys, mountains and deserts of Southern California.
Elevated surf and dangerous rip currents were also expected through Monday night. Surf up to 3 to 5 feet can be expected across south-facing beaches, according to the NWS, which warned swimmers to stay out of the water or swim near a lifeguard, and to avoid rock jetties, walls and cliffs.
A gradual cooling trend is expected to begin Tuesday throughout the Southland, with highs dropping up to 8-10 degrees by next weekend.