An excessive heat warning scheduled to last through Thursday will go into effect in much of the Southland this morning, ushering in a four-day period of sweltering weather that will threaten to cause heat-related illnesses, especially among the very young and the elderly.
Daytime high temperatures will be in the 80s to low 90s at the coast and will soar to over 100 degrees inland, with the hottest days expected to be Tuesday and Wednesday, according to NBC4 meteorologist Shanna Mendiola.
There won't be much relief at night, with overnight low temperatures will offer little reprieve from the heat, with temperatures still in the 70s and 80s.
The conditions will create dangerous situations, especially for those working outdoors.
It will also create an increased potential for power outages because of the widespread use of air-conditioning.
California Independent System Operator issued a Flex Alert for Tuesday and Wednesday from 5 p.m. to 9 p.m., asking residents to conserve energy when safe.
Southern California residents are urged to take steps to protect themselves from the conditions, scheduling strenuous activities for the coolest part of the day -- in the morning or evening -- wearing lightweight and light-colored clothing and drinking plenty of water.
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The excessive heat warning will be in force along the LA County coast, in beach cities, metropolitan Los Angeles, Downtown L.A., and the Hollywood Hills; the San Gabriel, San Fernando, Santa Clarita and Antelope valleys; the San Gabriel and Santa Monica mountains; and inland Orange County, where highs will range from the mid 90s to 104.
There is also an elevated fire danger with the dry conditions.
Also in effect today is a high surf advisory scheduled to expire in L.A. County at 8 p.m. and in Orange County at 9 p.m.
In Orange County, forecasters expect surf of 5-8 feet along with occasional 10-foot sets.
Temperatures will remain high throughout the week.
City News Service contributed to this report.